ZOOLOGY A.VD BOTANY, MIOJROSCOPY, ETC. 193 



of the glands or crypts diverges from that of open glands ; it gives rise 

 to a mass of reticular tissue producing fluid and corpuscles, which pass 

 into the blood. 



Account of the Hoatzin.* — C. W. Beebe gives an account of the 

 feeding and breeding habits and other cecological relations of this 

 extremely interesting bird, Opisthocomus hoatzin, which he had the 

 fortunate opportunity of studying in Venezuela and British Guiana. 



Immunity to Viper Venom. — G. Billardt and E. Maublaut find 

 that the common duck shows a remarkable indifference to the venom 

 of the viper. The same is true of the owl (cheveche commune). Two 

 were bitten badly on the feet, but did not seem much the worse. 



G. Billard \ also finds that the domestic cat has almost complete 

 immunity as regards the neurotoxin of the viper. Perhaps this is true 

 of many Felidas. 



Evolution of Reptilian Scales. § — Georg Stehli has studied the 

 development of the bony scales in Anguis fragilis and in Gongylus 

 ocellatus, the segmental arrangement of the scales in lizards and snakes, 

 the cutis-ossifications in the crocodile and in Chelonians, and the seg- 

 mental arrangement of the integumentary bones in Aetosaurus ferratus 

 (Triassic). With Hasse and Otto he concludes that in Reptiles a seg- 

 mental arrangement of scales is primitive, and that each horny scale 

 originally belonged to a subjacent bony scale. The phyletic stages are : — 

 (1) segmental horny scales, with subjacent bony scales ; on each segment 

 one row of scales, or sometimes, by doubling, two rows ; (2) breaking 

 up of the bony scale into mosaic-like plates (as in Scincoids) ; (3) dis- 

 appearance of the bony scale ; (4) multiplication of the horny scales, 

 and loss of the segmental arrangement. 



Ear of Urodela.|| — K. Okajima has studied the structure of the ear 

 in Megalobatrachus, Siredon, Onyckodactylus, Hynobius, Triton, and 

 Salamandra, and finds that there are at least three apertures for the 

 auditory nerve in the internal vestibular wall. The nerve divides on its 

 entrance into three or more branches. Those that traverse the median 

 apertures always go to the sacculus. 



Total Closure of Gut in Healthy Frog.T — H. Fischer describes a 

 curious case of a specimen of Rana escidenta which seemed in good 

 condition, but showed on dissection an enormously dilated rectum which 

 ended blindly. The sac was full of blackish green material, and the 

 abnormality must have persisted for a long time. It seems necessary 

 to suppose that remains of the food must have been passed out by the 

 mouth. 



* Zoologica, New York Zool. Soc, I., No. 2, Dec. 1909, pp. 45-66 (9 figs.). 

 See also Zool. Zentralbl., xvii. (1910) p. 637. 



t C.R. Soc. Biol. Paris, lxix. (1910) pp. 316-17. 

 I Tom. cit. pp. 318-19. 



§ Jen. Zeitschr. wiss. Zool., xlvi. (1910) pp. 737-800 (1 pi. and 19 figs.). 

 || Arch. Biol., xxv. (1910) pp. 77-98 (1 pi.). 

 1 Anat. Anzeig., xxxviii. (1911) pp. 79-86 (1 fig.). 



