^{page 287 note *} C. ruscifolia is commonly known as “tree-toot.” It grows to a variable height, sometimes to 6–8 metres, and has glossy, succulent leaves and shoots. C. thymifolia or “ground-toot” usually grows to 30–50 cm. in height, and has small leaves and flowers. C. angustissima is herbaceous, and grows about 50 cm. high. Its slender branches terminate in very fine branchlets which carry numerous leaves, thus giving the plant a fern-like appearance. It is comparatively rare.

^{page 287 note †} “On the Toot Plant and Poison of New Zealand,” Brit, and For. Med.-Chir. Rev., July 1865, p. 153.

^{page 287 note ‡} These were kindly sent to me by Mr Aston.

^{page 288 note *} Trans. N.Z. Instit, vol. ii. p. 399 [1869].

^{page 288 note †} Trans. N.Z. Instit, vol. iii. p. 242 [1870].

^{page 288 note †} Trans. N.Z. Instit, vol. ii. p. 153 [1869].

^{page 288 note §} Dr Lauder Lindsay (l.c.) mentions that Dr Murray Thomson of Edinburgh undertook a chemical investigation of the specimens brought home by him, but owing to Dr Thomson's removal to India the research was not completed. Skey also states that, “a great many experiments have from time to time been made upon the toot plant with the object of extracting the formidable poison known by sad experience to exist therein”; but as no other mention is made of these, they had probably ended in failure.

^{page 289 note *} Trans. N.Z. Instit., vol. iii. p. 237 [1870].

^{page 289 note †} Trans. Chem. Soc., vol. lxxix. p. 120 [1900].

^{page 289 note ‡} Trans. N.Z. Instit., vol. iii. p. 241 [1870].

^{page 289 note §} N.Z. Med. Journ., 1890, July and October.

^{page 291 note *} In a “Report on the Physiological Action of Tutin” by Dr Fitchett and Professor Malcolm, published in the Annual Report of the New Zealand Department of Agriculture for 1908, which has reached me since the above was written, the minimal iethal dose of tutin by hypodermic injection (unless otherwise stated) is given in mg. per kg. body-weight as follows:— cats, 0η75; guinea-pigs, 2; rabbits, 2·5; lizards, 3–4; birds, 10·5 (by oral administration); frogs, 10·5; fishes, 50 (when immersed in the solution). An extended report by Fitchett and Malcolm has appeared as this paper is passing through the press (see note at end).

^{page 292 note *} It is well known in New Zealand that tooted sheep may not show any abnormal symptoms if left alone, but if driven they become excited and enter into convulsions.

^{page 307 note *} Gottlieb (Arch. f. exp. Path. u. Pharm. vol. xxx. p. 21) has shown that in dogs kept for several days to allow the shock of the operation to pass away, convulsive movements can he produced in the hind limbs by picrotoxin after section of the spinal cord, and that in certain fishes and amphibians and very young mammals convulsive movements can be induced by this drug behind a spinal transection soon after the operation. He failed, however, to get any evidence of spinal stimulation in pithed frogs. See also note at the end of this paper.

^{page 310 note *} Loc. cit.

^{page 311 note *} Archiv f. exper. Path. u. Pharmak, xxxviii, p. 397 [1897]; xl. p. 151 [1897].

^{page 311 note †} Archiv f. exper. Path. u. Pharmak, xxxviii, p. 421; xl. p. 152.

^{page 311 note ‡} Archiv f. exper. Path. u. Pharmak, xlv. p. 272 [1901].

^{page 311 note §} Archiv f. exper. Path. u. Pharmak, 1. p. 247 [1903].

^{page 312 note *} Loc. cit.

^{page 313 note *} Recherches expérimentales sur le principe toxique du redoul, Paris, 1863.

Note.—Since the preceding paper was accepted for publication a research on the Physiological Action of Tutin by Fitchett and Malcolm has appeared in the Quarterly Journal of Experimental Physiology (vol. ii. p. 335; Oct. 1909); an extended description of the research, with protocols, being given by Fitchett in the Transactions of the New Zealand Institute (vol. xli. p. 286). The effect of tutin on various classes of animals is described, and, in so far as our experiments are common, our results are in general agreement. On a few physiological points we are not in accord. Fitchett and Malcolm have apparently not obtained any evidence of stimulation of the cardio-inhibitory centre, but they appear to have investigated the matter only in animals under anæsthetics. As I have shown, no decided stimulation of this centre occurs during surgical anæsthesia.

They also attribute to the motor area a smaller and to the spinal cord a larger share in the production of the convulsions than I have done. They state that after inducing convulsions in a cat under chloroform by a large dose of tutin injected hypodermically and removing the right cerebral hemisphere, “the convulsions continued just as before, affecting both sides equally,” and after scooping out the left cerebral hemisphere “the convulsions seemed to be quite unaffected.” “The spinal cord was then divided in the mid-dorsal region. The movements below the level of section were absent or abolished at first, but four minutes after the section clonic and tonic spasms of the hind limbs were observed, and these continued intermittently until death ensued, a quarter of an hour later.” The continuance of the convulsions after removal of the cerebral hemispheres is explained by the fact that, according to the protocol of the experiment (No. 152 in Fitchett's paper, p. 356), the anæsthetic was stopped when the tutin was administered—twenty-two minutes before the appearance of any symptoms. The only difference in our results is the effect obtained behind a transection of the spinal cord. All my transection experiments were made on rabbits, but since the appearance of Malcolm and Fitchett's paper I have repeated two of the experiments on cats. In both cases the animals were anæsthetised with chloroform and the anæsthesia maintained with ether. In one animal 0·02 grm. tutin was injected into the external jugular vein, and five minutes after the hind limbs were seen and felt to twitch the spinal cord was completely divided at the level of the 11th dorsal vertebra. The convulsions in the parts innervated beyond the section immediately ceased, and they did not recur. Apparent convulsive movements in the hind parts appeared, but, as in experiments on rabbits, they were synchronous with the clonic convulsions occurring in the fore part of the body, and by careful palpation were proved to arise in the muscles innervated anteriorly to the spinal section. The muscles of the hind limbs were palpated for forty minutes after the transection, but no twitch was felt in them. In the second experiment the mid-brain was cut across just above the pons, and the brain above the section removed. The administration of ether was then stopped. Twelve minutes later (3.28) 0·02 grm. tutin was injected intravenously. Twitches of the eyelids and ears occurred at 3.37, and slight convulsive movements of the limbs at 3.42. These quickly became more severe, and at 3.51 the cord was completely divided at the level of the last dorsal vertebra. Slight independent movements of the hind limbs occurred at 3.54, and became more marked and assumed a more convulsive type later. Pressure on one hind foot excited convulsions in both hind limbs. The convulsions, however, were not so characteristic as those in the fore part of the body. The animal died at 4.15. This experiment, therefore, confirms the observation of Malcolm and Fitchett that tutin acts on the spinal cord in cats; and the first experiment seems to show that this effect, like that upon the lower cerebral centres, is very susceptible to anaesthetics.