ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 43 



nucleus ; in any case it has an incomplete vital energy which it acquires 

 from the nucleus. The organic products obey physico-chemical laws ; 

 the energid produces an energy special to life. J. A. T. 



Blood as Food.— Hassan el Diwany {G. R. Soc. Biol., 1919, 82, 

 1282-3). A study of the digestive tract of the medicinal leech and 

 Hemiclepsis tesseUata, and also of a tick (Ixodes ridiwms), which furnishes 

 evidence that the intestinal cells break up the molecule of haemoglobin, 

 giving rise not only to biliary pigments which are eliminated, but also 

 to utiUzable materials which are absorbed. The latter include fat and 

 iron-compounds. J. A. T. 



Reduction of Jugal in Mammals. — L. T. Hogben (Proc. Zool Soc. 

 London, 1919, 71-8). An account is given of the state of the jugal in 

 a variety of mammalian types. " Seeing that in a diversity of isolated 

 genera among the Placentals exhibiting every possible variety of diet 

 and habit, and also in some of the less specialized representatives of 

 the larger groups themselves, the jugal displays essentially the same 

 relations as in the Metatheria — namely, extending postero-ventrally from 

 the glenoid to the lachrymal antero-dorsally — it is hardly possible to 

 agree with Weber that the jugal was small in the earliest Mammalia, as 

 in the Insectivora of to-day : on the contrary, there can be little doubt 

 that this represents the ancestral condition retained by the class till a 

 date later than that at which the modern lines of mammalian descent 

 had become differentiated." In Monotremes, though the arch is strong, 

 the jugal is vestigial or absent. Reduction is common, but the reason 

 for it is obscure. J. A. T. 



New Adaptive Callosity in Ostrich. — J. E. Duerden (Records of 

 Albany Museum, 1919, 3, 189-95). At a certain stage in its develop- 

 ment, the two-toed Ostrich {Struthio) has three toes and hints of four 

 and five. Two or three toes have been lost, but the loss is not quite 

 complete. When crouching the ostrich rests on the tip of its partly 

 bent toes and upon the ankle-end of the tarso -metatarsus. There are 

 callosities on the toes and ankle, and these occur on chicks before 

 hatching. They are part of the inheritance. But besides the median 

 ankle callosity there is an accessory ankle callosity, which begins to form at 

 an early chick stage, and becomes gradually larger and coarser. This 

 accessory pad is more practically useful than the inborn ankle callosity. 

 But it is not known to be transmissible. " In many respects the ostrich 

 appears to have reached senility, and it may be that structural changes 

 resulting from external stimuli are now more likely to remain transient, 

 instead of becoming impressed permanently upon the organism. This 

 may assist in some measure in understanding why the later accessory 

 ankle callosity has not become hereditary, and also why the median 

 callosity, though unused, continues to appear generation after 

 generation." J. A. T. 



Action of Snake-poison on Blood. — B. A. Houssay and A. 

 SoRDELLi (C. R. Soc. Biol., 1919, 82, 1029-.31). Twenty-one different 

 kinds of snake-poison have been studied. All these destroy the 

 cytozyme (thrombokinase) by their lipolytic power. This soon stops 



