220 



SCIENCE-GOSSIP. 



chicken bitten by a young heloderm died in twelve 

 hours, and a cat, though it ultimately recovered, 

 was very seriously affected. He remarked that 

 with a more developed lizard the symptoms would 

 have probably been much more severe. According 

 to Boulenger, the poison is very active, causing 

 the death of guinea-pigs in two or three minutes, 

 with symptoms very similar to those following the 

 bite of a viper. 



Sir Joseph Fayrer also came to the conclusion 

 that this reptile was venomous, for he found that 

 two guinea-pigs bitten in the morning both died 

 before night. He suggested the theory that it was 

 possible that all saliva contained a certain amount 

 of the active principle which was most developed in 

 venomous serpents, and that the gila monster 

 might have more of this than was possessed by 

 other lizards. 



The most extensive investigation of the subject 

 which has been published, was that made by Prof. 

 Weir Mitchell and Dr. Reichert in Philadelphia. 

 They obtained the poison by causing the lizard to 

 bite a saucer and collecting the saliva as it dropped 

 in small quantities from the lower jaw. It had a 

 faint aromatic smell and a distinctly alkaline 

 reaction. When mixed with water and injected 

 into the breast of a pigeon, it caused rapid respira- 

 tion, convulsions, and death in seven minutes. 

 There were no local effects about the wound as is 

 to be seen in the case of rattlesnake poisoning. 



An interesting case of the effect of the bite on 

 the human system, is described by Dr. Schufeldt, 



who experienced it in person. When returning a 

 specimen to its cage, he was severely bitten on the 

 thumb. The bleeding soon ceased but severe 

 shooting pains followed with rapid swelling of the 

 arm and general faintness. In the course of a day 

 or two, however, all ill effects had passed away. 



Against all these witnesses we have to place the 

 negative testimony of Dr. Yarrow, who repeated 

 Prof. Mitchell's experiments without finding a 

 single case in which the bite or saliva was venomous. 

 The saliva, obtained by making the heloderm bite 

 indiarubber and collecting the drops with pellets of 

 cotton wool which were subsequently washed with 

 glycerine, was injected into rabbits and chickens 

 without any lasting ill effects. The same results 

 followed bites from the lizard, and although care was 

 taken that the saliva should enter the wound, in 

 no case were there any symptons of poisoning. A 

 young chicken, for example, bitten on December 

 5th, was perfectly well on December 7th. 



From these different observations, all by reliable 



authorities, we must conclude that the bite of the 



gila monster may sometimes be extremely poisonous 



to small animals, while at others it is much less so, 



and that it may even be without any effect at all 



beyond the injury inflicted by the teeth. It should 



be noticed, however, that Dr. Yarrow's experiments 



were made in the winter, and that just as serpents 



secrete less venom in the cold weather, so the 



heloderm may also secrete less or even lose its 



power of secretion altogether. 



33, Waldegrave Road, Upper Norwood, S.E.; 

 November, 1894. 



RUST IN WHEAT AND BARBERRY BUSHES. 

 By George H. Pethybridge, B.Sc. 



'THE cause of the disease known as "rust" in 

 wheat and other cereals was for a long time 

 not understood, and even now it is doubtful 

 whether the mystery has been completely solved. 

 A study of the facts, however, which are known to 

 us concerning the cause of the 

 disease may prove useful and in- 

 structive. 



The wheat crop begins to show 

 the first signs of the disease in the 

 months of June or July. One 

 may notice during these months 

 that the usually bright green 

 leaves are beginning to assume 

 their autumnal tint, as if becoming 

 ripe too early. On close examina- 

 tion, however, it will be seen that 

 z the yellow colour of the stem and 



Fig. 1.— One of the leaves is due not to the ripening 

 spots at which the f t he corn, but to a number of 

 yellow spores are 

 formed (magnified), yellow patches and lines (fig. 1) 



which are covered by a fine yellow sulphur-like 

 dust, which can easily be rubbed or shaken off 

 from the plant. By watching the field of corn 

 from day to day for some time, it will be found 

 that the number of these yellow patches increases 

 from plant to plant rapidly, until it may be 

 that there is scarcely an uninfected plant in 

 the whole field. If some of the yellow dust be 



)«f© @ 



Fig. 2. — Transverse section through a portion of an infected 

 stem (magnified).— e, ruptured epidermis ; y s, yellow uredo- 

 spores ; c, cells of tissue of stem, with interwoven filaments. 



