ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 185 



to the development of the chick. In cocks it is usually 42° and a small 

 fraction, but they are more perturbed by the experiment. 



Colour Variation in the Swan.* — F. A. Forel has an interesting 

 note on this subject. In 1868 he noted the sudden appearance in a 

 brood of cygnets of Gygnus olor L. hatched at Morges, of a well-marked 

 colour variety. The cygnets displayed a white instead of a grey down, 

 their first feathers wero also white, the beak and feet a greyish-rose colour. 

 The eye was normal, and no signs of weakness of any sort were ap- 

 parent ; this sport he described as false albinism. Since 1868 the variety 

 has appeared in increasing numbers in the half-wild swans of the Lake 

 of Geneva, and has also occurred, though less frequently, in the domesti- 

 cated swans of the town. The origin both of the town swans and of those 

 of the lake is known, and also the date of the first appearance of the 

 variety. Since its first appearance it has reappeared each year in most 

 of the broods of the different shores of the lake, so that there is every 

 reason to believe that the variety will in the course of time become fixed 

 as a new species. It is to be regarded as a progressive variation, for it 

 is virtually a premature adoption of the adult tints. An interesting 

 point is that the same variety has, although very rarely, made its ap- 

 pearance elsewhere, e.g. at Nimes in 1898 in one cygnet in a brood of 

 six typical forms. 



Accessory Bladders of Turtles.f — Mr. F. W. Pickels finds these 

 organs in semi-terrestrial and semi-aquatic Testudinata ; they are want- 

 ing or greatly reduced in the strictly aquatic and strictly terrestrial 

 forms. " The author believes that these bladders are receptacles for 

 liquid stored up for the use of the animal, but he could not confirm 

 the statement of earlier observers that the fluid was water taken in 

 through the cloaca." 



Peculiar Salamander.! — W. E. Ritter and Love Miller give an 

 interesting account of some of the peculiarities of Autodax lugubris 

 Hallow, one of the Plethodontidas, confined along with two other species 

 to western North America and almost entirely to California. It is 

 entirely terrestrial, and seems to bo indifferent even to a proximity to 

 water; like many of the long-tailed ampkibians it is lungless ; the 

 author's observations support the view recently defended by Bethge 

 that, in the absence of both gills and lungs, respiration is performed 

 hy the mouth-epithelium and the integument together, each taking 

 an essential part. In regard to the embryos, particular attention is 

 directed : — (a) to the great quantity of yolk in the eggs and the abun- 

 dant vitelline circulation ; (b) to the very large three-lobed gills ; and 

 (c) to the entire absence of a larval period, even the gills having almost 

 entirely disappeared at the time of hatching. It is to be hoped that 

 we shall soon have full details in regard to the development of this 

 interesting form. 



Salamanders with and without Lungs.§ — Dr. E. Lonnberg adds 

 two species to the list of salamanders that are normally without lungs, 



* Arch. Sci. Phys. et Nat., viii. (1899) pp. 490-1. 



t Zool. Bull., ii. (1899) pp. 291-301. See Amer. Nat., xxsiii. (1899) pp. 976-7 



X Amer. Nat., xxxiii. (1899) pp. 091-704 (7 rigs.). 



§ Zool. Anzeig., xxii. (1899) pp. 545-8. 



April 18th, 1900 



