The early accounts of the morphology and life-cycle of Heterodera schachtii, were, like much of the subsequent work on this subject, the result of observations carried out on the strain of H. schachtii parasitic on sugar-beet in Germany.

Galls, in the inflorescences of various species of grasses, caused by nematodes have been known since Steinbuch first described them, in 1799, in the flowers of Agrostis capillaris and Phalaris phleoides. Since that time they have been found in several other species of grasses and have been studied principally by entomologists interested in galls caused by insects. The causative organisms have received but little serious attention from helminthologists in recent years.

(1) During the routine examination of the fauna of samples of clinker removed from the filter beds of Brent Sewage Farm several species of Rhabdilis were met with, one at least of which cannot be relegated to any species as yet described. A new species is therefore suggested for its reception and the name succaris has been given to suggest its origin from the sewage farm.

(2) An account is given of its structure. While being typical for the genus, the lips and bursal rays do not agree with any known species.

(3) Two distinct strains were reared by means of different culture media, differing quite definitely in length. A thousand worms were measured and these differences were found to remain very constant. The relative measurements have not been materially altered.

(4) The length of the large worms has been diminished by means of a return to the original food.

(5) The cultivated strain shows greater variability than the original strain.

(6) Two graphs and a table summarising the results are shown.

In the majority of cases it is almost impossible to identify the species of helminths in our domestic stock by an examination of the eggs found in their droppings. In the case of sheep and goats, this is particularly so since these hosts harbour several worms with eggs which are, apparently, identical in shape, size and stage of development.

The lungworm genus Crenosoma, founded by Molin in 1861, was redescribed in 1928 by Skrjabin and Petrow. To the two existing species, C. striatum (Zeder, 1800) from the hedgehog (Erinaceus europæus L.) and C. vulpis (Dujardin, 1845) from the fox (Vulpes vulpes L.), these writers added a third species, C. taiga, from the lungs of Kolonocus sibiricus (Pall.) in Russia. A generic diagnosis based on a study of these three species was supplied, and the wolf (Canis lupus L.) was recorded as a new host for Crenosoma vulpis.

Of the insects responsible directly or indirectly for losses in plant industry the Scolytidæ or bark-beetles are well known, particularly to those associated with the practice of forestry, in Europe and America through the effects of their outbreaks. Bark-beetle attacks have resulted in serious damage in many parts of the world although in Britain their depredations have been less severe probably owing to the limited extent of forest lands.