FRESH FACTS. 



The Shell of a Turtle. H. Gadow. " Orthogenetic Variation in the 

 Shells of Chelonia," Proc. Cambridge Phil. Soc. x. 1899, pp. 35-37. The 

 normal shield of the Loggerhead turtle (Thalassochelys caretta) possesses six 

 median (including the so-called nuchal) and five pairs of costal scutes. Of a 

 total of 56 specimens not less than 43 were abnormal, i.e. 76 - 6 per cent. Of 

 41 newly-hatched specimens not less than 38 were abnormal, i.e. 92*7 per cent. 

 The variations are manifold, the number of median scutes varying from 8 to 7 to 6, 

 the costal scutes ranging from 7 to 6 to 5, and they are either symmetrical or 

 uneven. Most of the individuals seem to grow out of these irregularities, 

 which the author regards as "atavistic reminiscences," and the reduction or 

 squeezing-out of the supernumerary scutes proceeds in a very regular way, 

 suggestive of "orthogenesis," it seems. 



Poison or Centipedes. O. Duboscq. " Sur l'histogenese du venin de la 

 scolopendre," Arch. zool. exper. vi. 1898 (Notes et Kevue) pp. xlix-li. Part of 

 the poison is formed in the nuclei of the glandular cells at the expense of the 

 chromatin, a histological result which agrees with the chemical one that certain 

 active components of poisons are nucleo-albumins. 



Secretion of Poison in the Adder. W. Lindemann. " Ueber die 

 Secretionserscheinungen der Giftdriise der Kreuzotter," Archiv mikr. Anat. 

 liii. 1898, pp. 313-321, 1 pi. The process of venom-secretion is closely 

 analogous to that in an ordinary salivary gland. Homogeneous drops appear 

 in the cell-substance which becomes clearer. The periphery becomes darker 

 as the drops are discharged. 



Castrating Caterpillars. J. Th. Oudemans. " Falter aus castrirten 

 Raupen, wie sie aussehen und wie sie benehmen," Zool. Jahrb. xii. 1898, pp. 

 71-88, 3 pis. 2 figs. The experimenter has not only shown that it is possible 

 to castrate caterpillars, which is surprising enough, but that the process has no 

 effect on the external appearance of -the adults as regards secondary sex char- 

 acters, which is even more surprising. Even the habits were little affected, 

 thus copulation occurred though there were no spermatozoa. The organism is 

 indeed a unity, and more than a correlated congeries of parts ! 



Inoculation for Tick Fever. C. J. Pound. " Note on Tick Fever in 

 Cattle," Jonrn. QuekettMicr. Soc. vii. 1898, pp. 118, 119. The author claims 

 to have worked out protective inoculation for tick fever. Some thousands of 

 cattle have been inoculated, and the results have proved highly satisfactory, for 

 when such cattle were subjected to gross tick infection, or injected with virulent 

 blood, they remained perfectly immune. But no statistics are given in the 

 brief paper. 



Hairs of Monotremes. Baldwin Spencer and Georgina Sweet. " The 

 Structure and Development of the Hairs of Monotremes and Marsupials, Part I. 



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