The economic importance of the leaf-roll disease of potatoes has been recognised for a number of years owing to the fact that its incidence leads to a heavy reduction in marketable ware. The annual loss to potato growers in England and on the Continent from leaf-roll amounts to a high figure, but the disease is not of such prime importance to the Scottish cultivator as certain other diseases of the virus class to which the potato is prone, namely, mosaic and crinkle.

The first known fossil Ostracoda were collected by the Rev. David Ure from the Carboniferous Limestone of East Kilbride. In 1793 he figured his specimens, describing them merely as “microscopic shells.” Some years later Dr S. Hibbert (1836) described and figured as Cypris scotoburdigalensis some Ostracoda he had collected from the Burdiehouse Limestone near Edinburgh. The most important work on this group of fossils was done by T. R. Jones. In 1866, together with J. W. Kirkby, he gave a short account of previous research, and from 1855 until 1901 published a large number of papers, either alone or in collaboration with J. W. Kirkby, H. B. Holl and others, mainly in the Annals and Magazine of Natural History. In 1927 Dr Hopkins used an ostracod bed for correlation purposes in the Northumberland and Durham Coalfield, and in 1931 W. B. Wright observed that the ostracods show a definite succession of forms. A new species described by Wright as Cytherella foveolata occurs at the top of the Pulchra Zone and may be of zonal significance since it has not so far been recognised in any other horizon.

The author recalls the facts regarding the rediscovery, in recent years, of Carter's genus Conulites ( = Dictyoconoides Nuttall). He shows how, of seven species which have been referred to this genus, three always have numerous intercalary whorls in their spires, and four never have any such whorls. The association of these two groups together within a single genus has, so far as he himself is concerned, been due to the uncertainty hitherto existing regarding the type species cooki, whose spire was stated by Carter sometimes to show an intercalary whorl, but generally to be “single throughout.” Carter's original specimens, which had long been mislaid, have recently been found, however, and they all prove to belong to now familiar types, which invariably contain numerous intercalary whorls in their spires. The author therefore separates the four species which do not possess such whorls into a new genus, Lockhartia.

The author next discusses the supposed identity of Dictyoconoides with Rotalia, and shows that the Rotalia must be judged by their type species R. trochidiformis. He shows that this species, among other characteristic features, invariably displays the structures called “astral lobes” by Carpenter and Brady, and is distinguished by the same from both Dictyoconoides and Lockhartia; while it is further distinguished from Dictyoconoides by the absence of intercalary whorls in its spire.

The author then compares the development of Rotalid forms, like the above, with that of piano-spiral ones like Nummulites and Assilines; and he finally shows the fundamental difference in structure between all these spirally wound types and those with an “end-on” development, like the Dictyoconus group of forms, with which some of them have been confused in the past.

Although it is unlikely that the east of Sutherland will ever rival the west in geological renown, its varied interests have already furnished material for a considerable literature. Attention has been specially focussed upon a down-faulted coastal strip of Mesozoic rocks, which, starting at Golspie, extends north-eastwards for twenty miles through Brora and Helmsdale to the county boundary at the Ord (fig. 1). Golspie itself stands on a narrow outcrop of Trias. Jurassic follows, with a generally ascending sequence that leads up to Kimmeridgian at Kintradwell, a couple of miles north of Brora (fig. 2). Beyond this Corallian reappears, but only for a short distance. Then Kimmeridgian returns and holds the coast-line continuously for nearly nine miles, until, at the Ord, it disappears beneath the sea. The width of the Kimmeridgian exposures is occasionally three-quarters of a mile, but generally much less.

The remarkable and close parallelism exhibited by the suctorial disc of the fish Garra and of certain tadpoles belonging to frogs of the section Rana formosa of Rana was pointed out by the late Dr Annandale and myself in 1922. Evidence was then adduced to show that such structures have come into existence through a gradual accumulation of small changes, which probably originated in direct response to the increasing swiftness of the currents as the animals invaded higher and higher levels of torrential streams. The probable evolution and the development of the disc of Garra have been described already (Hora, 1921, pp. 639–643); whereas the peculiar structure of the disc in the tadpoles has hitherto been known only in its fully-formed condition. It seemed probable that, with the discovery of the earlier stages in the development of the disc, the line of evolution of the sucker would prove to be similar to that of the sucking disc of the fishes of the genus Garra (Hora, 1930, p. 241). The observations described hereafter confirm this view.

Our knowledge of the nature and mode of action of the nervous mechanism of the uterus is far from complete. The following paper is a continuation of that published by the Royal Society of Edinburgh in 1927 (38).

In that paper a short historical summary of the previous work was given. To expand this summary and fully analyse the further papers I have studied on the special points of my present communication would unduly lengthen this memoir. I will therefore confine myself to a brief abstract of my former results, and a short statement as to the present state of our knowledge. A full bibliography will be found at the close of this communication.

It is well known that there are two distinct horizons in the Caledonian Lower Old Red Sandstone which contain abundant plant-remains (Evans, 1929). At the lower horizon of the Carmyllie and Cairnconnan Beds the flora consists, so far as is clearly known, of Pachytheca, Nematophyton, Parka, and one vascular plant, Zosterophyllum myretonianum (Lang, 1927). In certain greenish-grey flags and sandstones of the Strathmore Beds near the summit of the stratigraphical succession fragmentary plant-remains are abundant along a line stretching from Rosemount, south of Blairgowrie, through Murthly, Glenalmond, Callander, and Balloch, to near Brodick in Arran. From these beds a small but quite distinct assemblage of fossil plants is known. Pachytheca is clearly recorded. The well-defined remains of vascular plants have so far all been referred to Arthrostigma gracile, Dawson, and Psilophyton princeps, Dawson. References to Psilophyton robustius occur, but there is no evidence that the type of plant distinguished from Gaspé under that name has been found in the Strathmore Beds.

While an endodermis in the leaf is a relatively rare occurrence amongst the Angiosperms, its presence has been noted as being fairly constant in a number of families; but it is only in the case of a few of these families that it has been treated in sufficient detail to indicate its representation generically. Mylius (8), in particular, has examined the foliar endodermis of the Myrtaceæ, the Onagraceæ, and the Rosaceæ; especially the latter family, in which he makes a comprehensive investigation of the genera Spiræa, Alchemilla, Fragaria, Potentilla, Rosa, Agrimonia, and Sanguisorba (Poterium) from this standpoint. An endodermis has also been recorded as present in the leaves of certain Monocotyledonous families of which the Bromeliaceæ, Orchidaceæ, and Gramineæ (tribe Festuceæ) are examples quoted by Haberlandt (4, p. 368 sqq.) from the work of Rimbach, Schwendener, and van Wisselingh.

The Kidston Collection of fossil plant slides in the Botany Department of the University of Glasgow contains a number of sections of a very notable stem labelled “Lepidodendron textum, Kidston, n.sp.” No mention is made of this species in any of Dr Kidston's publications, but the correspondence relevant to the Collection indicates the history of the slides. This may be briefly summarised.

As early as 1883, Dr Kidston had received from Mr J. Coutts two sections (Nos. 51 and 52) of this stem, which had been collected by the latter at East Kilbride, Lanarkshire, Scotland, from the Carboniferous Limestone Series of the Calderwood Beds (Hosie Limestone) in the Lower Limestone Group. Dr Kidston postponed description of this stem till he had better sections at his disposal; the specimen, however, was lost, and it was not till many years later that he rediscovered it in Dr John Young's collection in the Glasgow Municipal Museum, and had more sections cut from it (Nos. 1144–1153). No manuscript notes of Dr Kidston's descriptive of these slides have been found, with the exception of a pencilled reference in his manuscript slide catalogue, opposite Nos. 51 and 52, to the “foliar bundles—there is an appearance as if there was a development of secondary xylem, whereas the axial bundle has no secondary wood.”

The limestone to be described occurs in two separate areas (fig. 1)—one in Lower Deeside around Banchory, another in Middle Deeside around Aboyne. The whole of the Banchory and a large part of the Aboyne outcrops provide limestone types in a high grade of regional metamorphism (the associated schists contain sillimanite). In the latter outcrop the limestone has undergone thermal metamorphism at the contacts with Newer Granite intrusions. Many of the resulting hornfelses have suffered hydrothermal alterations with development of prehnite and zeolites. Newer Granite pegmatites, intruded at the time of hornfelsing, share in this hornfelsing and later hydrothermal modifications. In addition, they exercise exopneumatolytic and exohydrothermal metamorphism. Quite local metamorphisms take place at hornblende-schist and Older Granite contacts.

In the species Cavia the female passes into a condition of heat immediately, or almost immediately, after the birth of a litter, and pregnancy can be repeated without any interval. The new blastocysts reach the uterine cavity on the fifth day after parturition, and during the first seven days of pregnancy extensive reparative changes take place. These changes involve not only the healing of the placental site but a shedding and restoration of the epithelial lining of the uterus. As this process does not seem to have been investigated in detail in the guinea-pig, it is proposed in this paper to describe briefly the histological changes occurring in uteri at different times post partum in non-pregnant animals. It will be necessary, however, before describing the histological details of these post-partum changes to give a brief summary of the observations of other investigators on the ante-partum changes associated with the implantation of the blastocyst, the subsequent obliteration of the uterine cavity, the formation of the decidua capsularis, and the reappearance of the uterine lumen.