710 SUMMARY OF CURRENT RESEARCHES RELATING TO 



organ in birds. It arises, as is well known, in the form of a diverticu- 

 lum from the cloaca. At the expense of the epithelium lining this 

 diverticulum buds develop, which penetrate into the " chorion " of the 

 mucosa. These epithelial buds represent the first stage of closed 

 lymphoid follicles ; the chorion corresponds to the dermis of the 

 diverticulum, and does not share in forming the follicles. The follicles 

 are distinctly haematopoietic. In a second stage the centre, and after- 

 wards the cortical portion, of the buds undergoes transformation into 

 reticulated tissue. Lymphocytes and blood-corpuscles cease to be 

 formed from the epithelium ; those formed are borne away in the 

 lymph-stream or in the blood ; a third adult stage is reached in which 

 the organ is practically a mass of fibrous connective-tissue. 



c. General. 



Immunity of Lerot to Viper's Venom.* — Gr. Billard had two lerots 

 bitten several times by large adders, but without effect apart from local 

 inflammation and loss of hair around the bite. A young badger bitten 

 by two very large adders, showed no ill effects. 



Apparent Bactericidal Influence of Colostral Milk.f — Max Bub 

 finds that the apparent germicidal property of colostral milk is, in the 

 main, due not to an actual killing off of the bacteria, but almost 

 exclusively to an inhibition of development. The agglutinins present 

 cause the germs to coalesce in balls. 



Variation in Skull of Sea-elephants. :{; — Einar Lonnberg has made 

 a minute study of the dimensions of the skulls of Macrorldnus, and finds 

 " exceedingly great variation." This is partly explained by the general 

 rule that large Mammals, the growth of which is continued through 

 a long period of years, each of which contains different seasons with 

 different conditions of life, are more apt to vary than such as conclude 

 their growth within one year. Another factor which may also be of 

 some importance in this connexion, is that the sea-elephants originally 

 had hardly any dangerous foes which could influence natural selection. 

 Now, unfortunately, these very interesting and completely harmless sea- 

 monsters are threatened with rapid extinction through human greediness. 



Rabbit and Hare.§ — J. P. Van Bemmelen has made a very detailed 

 comparison of the skulls of rabbit and hare, and his conclusion is, in a 

 sentence, that the rabbit is a transformed hare. All the differences in 

 the skulls are correlated with differences in the mode of life of the two 

 closely related forms. 



Hairs on Mole's Hands and Feet.|| — J. Kazzauder has found on 

 the proximal margin of the mole's palm a regular crescent of hairs in 

 several dense rows. They are partly sinus hairs and partly ordinary 



* C.B, Soc. Biol. Paris, lxviii. (1910) p. 982. 



t Centralbl. Bakt. Parasitenk., xxvii. (1910) pp. 321-36. 



% Proc. Zool. Soc, 1910, pp. 580-8 (2 figs.). 



§ Tijdsohr. Nederland. Dierk. Ver., xi. (1909) pp. 153-286 (107 figs.). 



|j Anat. Auzeig., xxxvii. (1910) pp. 4-5. 



