ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 17 



b. Histolog-y. 



Cultivation of Human Tumour Tissue in vitro.* — David Thomson 

 and J. G. Thomson have definitely succeeded in cultivating in vitro 

 portions of intracystic papilloma of the ovary (not truly malignant) and 

 of carcinomatous gland from the neck (secondary to carcinoma of the 

 floor of the mouth). In the first case, buds of new growing tissue 

 appeared on the third day, and the new cells differed markedly from the 

 original cells, being larger and with amoeboid processes. In the second 

 case, after 44 hours' incubation at 37* 5° C, long branching stroma 

 cells appeared growing out from the original tissue ; and the new cells 

 were again much larger than the original. It is interesting to note that 

 these human tumour tissues were cultivated in a medium composed 

 chiefly of fowl-blood plasma. 



Melaniridosomes.f — E. Ballowitz continues his study of chromato- 

 phores, and describes a new type in the perch and the ruffe {Acerina 

 cernua). The new type is a melaniridosome, which consists of a melano- 

 phore and an iridosome, i.e. a compacted aggregate of iridocytes (guanin- 

 cells). The iridocytes are numerous and the processes of the typically 

 central melanophore stream out between them. 



Theory of Action of Rays on Growing Cells.J — J. Joly compares 

 the events taking place in a photographic film with those which occur in 

 cells subjected to y- and 2>rays. The formation of the normal latent 

 image by moderate light-stimuli is parallel with the stimulation of growth 

 by feeble x- or y-radiation. The photographic reversal by greatly in- 

 creased illumination compares with the inhibition of growth by the 

 heavy doses of y-radiation now employed in the treatment of cancer. 

 If, in the life of the cell, ions are naturally always being formed, the 

 absence of a " restrainer " might lead to morbid ionization ; or, again, 

 the presence of a sensitizer. The. former would limit the ionizing 

 tendency either physically by its inert properties, or chemically. The 

 latter would accelerate it by removing the products of reaction as fast as 

 they are formed. It is interesting to note that excessive quantities of 

 radium are found in certain tumours. If the cancer cell be the seat of 

 excessive ionization, it may be possible to bring about reversal (as in the 

 radio-active treatment) or to devise some chemical treatment which 

 serves to discharge the ionized systems. 



Structure of Skin in AnguidseJ— W. J. Schmidt has made a 

 detailed study of the integument in Anyuis fragilis, Ophisaurus apus, 

 and Gerrhonotus liocephalus. With especial reference to the first, he 

 treats of the surface-relief ; the melanophores and guanophores ; the 

 arrangement of melanophores in epidermoid, subepidermoid, and inferior 

 groups ; the change in coloration with age ; the detailed structure of the 



* Proc. Roy. Soc, Series B, lxxxviii. (1914) pp. 90-1 (1 pi.). 



+ Zeitschr. wiss. Zool., c. (1914) pp. 1-35 (3 pis. and 8 figs.). 



% Proc. Eoy. Soc. Series B, lxxxviii. (1914) pp. 262-6. 



§ Zool. Jahrb., Abth'. Anat., xxxviii. (1914) pp. 1-102 6 pis. and 25 figs.) 



Feb. 17th, 191-', c 



