ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 575 



Darwinian hypothesis, but are inconsistent with the assumption that 

 brightly-coloured animals possess more than minimal conspicuousness 

 uncfer natural conditions. They impel one to reject the hypotheses of 

 warning and immunity coloration, signal and recognition marks, and 

 sexual selection, at least in so far as they may ever have been supposed 

 to apply to these forms. On the other hand, they confirm Thayer's 

 conclusions regarding the obliterative function of colour and pattern, 

 emphasize the common occurrence of adaptive characters among animals, 

 and suggest that their evolution has been guided throughout by natural 

 selection. 



Abnormality in Arterial System of Rabbit.* — Edmond J. Sheehy 

 describes a case in which the innominate artery gives off the two carotids, 

 but does not give rise to the right subclavian. A blood-vessel, serving 

 as a right subclavian — that is, supplying the right vertebral and the 

 arteries of the right arm — arises from the descending aorta dorsally and 

 slightly caudal to the left subclavian. It passes dorsal to the heart and 

 oesophagus, and appears on the right side in its proper position in the 

 vicinity of the first rib. The arrangement of the nerves is normal. 

 Abnormalities of a similar nature in the human subject have been 

 described and attributed to a persistence of embryological conditions. 

 The author explains this. 



Pectoral Girdle of Tetrapod Vertebrates.f— L. Yialleton has made 

 an interesting comparative study of the pectoral girdle in Amphibians, 

 Reptiles, Birds, Monotremes, and Eutheria. 



Striped Haddock in New Brunswick.^ — E. E. Prince describes 

 interesting striped specimens of the common haddock {Gadus aegUfinus). 

 They exhibit a series of broad bands and blotches of dark pigment on 

 each side of the body from the shoulder to the tail. Professor Mcintosh 

 has pointed out that the minute larval cod is marked by a series of 

 transverse bars; but the larval haddock is not. The black stripes 

 disappear on the adult cod ; a vestige persists in the haddock as the 

 "■ thumb-mark." Such blotches when repeated serially must be regarded 

 as atavistic, a reappearance of an ancestral trait or feature, which in 

 most specimens has practically disappeared. 



INVEBTBBIIATA. 



MoUusca. 

 «. Cephalopoda. 



Notes on Cephalopods.§ — ^Madoka Sasaki describes the first specimen 

 determined to be a male of the rare species, Amphitretus pelagicus Hoyle, 

 a jellyfish-like Octopod. He regards it as nearer to Polypidae than to 

 Cirroteuthis. Four new species of Polypus are described. 



* Sci. Proc. R. Dublin Soc, xv. (1916) pp. 159-62 (3 figs.), 

 t Bull. Acad. Sci. Montpellier, 1917, pp. 170-214. 

 % Contributions Canadian Biol., 1917, pp. 86-90 (1 pi). 

 § Annot. Zoo]. Japon., ix. (1917) pp. 361-7 (2 figs.). 



