ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 451 



Effect of Sterilised Air on Mammals.* — Dr. Kijanizin finds that 

 rabbits, dogs, and guinea-pigs, when supplied with sterilised air, die in 

 from 1^-5 days after introduction into the apparatus. Though the 

 absence of bacteria in food greatly lowers the power of assimilation, yet 

 death is evidently not due to this cause. Nor is it due to any toxic sub- 

 stance added to the air during the process of sterilisation, nor to in- 

 sufficient ventilation or similar cause. The exact cause of death was for 

 long a great puzzle, but an elaborate series of analyses showed the pre- 

 sence of a large amount of leucomaines in the urine, and led to the 

 conclusion that death is due to auto-intoxication with these. This result 

 leads the author to the following conclusion, which, as he notes, is of 

 great importance in biological chemistry : — " In addition to the oxygen 

 of the air, certain micro-organisms of the air are also absolutely neces- 

 sary to life and to the normal (respiratory) exchange ; these micro- 

 organisms are introduced into the blood at the moment of the gaseous 

 exchange, and are there devoured by the leucocytes. Digested by these, 

 they constitute the source of the oxidising ferment without which the 

 normal jjrocesses of oxidation in the organism diminish greatly, and give 

 place to the accumulation of a large amount of leucomaines, which are 

 intermediate products of incomplete oxidation, and lead to the death of 

 the animal." 



./Esthetic Judgments on Mammals. f — Prof. K. Mobius has entered 

 upon a field which the zoologist usually leaves alone. After a proposal 

 to substitute the objective word erhaltuntjsmassig for the transcendental 

 concept zweckmassig, he points out that erhaltungsmassig is not equivalent 

 to beautiful. He then passes the Mammals in review, and judges them 

 aesthetically. The proportions of the different parts of the body, the 

 real or apparent subordination of mere bulk, the attitudes, the eyes, the 

 coloration, and so on, are discussed, and the learned author is free with 

 the condemnation hdsslich. His judgments are in some cases very sur- 

 prising to us, but de gustibus non disputandum est. 



Monotremes and Reptiles.* — Prof. V. Sixta has worked out in 

 detail the homologies between the skulls of Psammosaurus griseus, Orni- 

 thorhynchus, and Echidna, and sums up his conclusions as follows. The 

 Monotremes possess au arcus, a cavitas temporalis, an os quadratum, as 

 do Eeptiles. Their os squamosale is the houiologue of that of Reptiles, 

 and the bony labyrinth in them is almost identical with that of Eeptiles, 

 while Jacobson's organ is similar in both. In Ornithorhynchus the upper 

 and under jaw have the same structure as in Reptiles. Generally the 

 skulls of Echidna and Ornithorhynchus are built on the Reptilian plan, 

 though in some respects they approach the Marsupial skull more nearly. 

 The Reptilian characters are most distinct in Ornithorhynchus ; the skull 

 of Echidna has diverged from the Reptilian type, and can only be under- 

 stood through that of Ornithorhynchus. 



Aglossal Toads.§ — Dr. W. G. Ridewood notes that, until the recent 

 discovery of Hymenochirus boettgeri, the new aglossal toad, the genera 

 Xenopus and Pipa occupied a very isolated position, their relations being 



* Arch. Biol., xvi. (1900) pp. 663-84 (1 pi.). 



t SB. Preuss. Akad., 1900, pp. 164-82. 



t Zool. Anzeig., xxiii. (1900) pp. 213-29 (3 figs.). 



§ Jouru. Linn. Soc, xxvii. (1900) pp. 454-62 (1 pi.). 



