142 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Artificially induced Mitosis.* — Mr. A. P. Matthews has succeeded 

 in setting up cell-division in unfertilised sea-urchin (Arbacia) eggs, 

 by depriving the eggs of oxygen, by the action of heat, and by sub- 

 jecting them to the influence of ether, alcohol, and chloroform. 



His theory is the following. All the methods thus far found for 

 inducing cells to divide are the methods in common use for causing 

 protoplasm to liquefy. As Biitschli said long ago, the karyokinetic 

 figure itself is but the expression of the movement of liquid in the cell. 

 In short, localised liquefaction induces karyokinesis. 



" The question naturally arises here whether these several agencies 

 •set up liquefaction by direct action themselves, or whether they inter- 

 fere in some way with the respiration of the cell, leading thereby to 

 the production of a liquefying enzyme, the centrosome. The general 

 phenomena of division strongly suggest a digestion of certain cellular 

 structures, the nuclear wall, nucleolus, yolk, and certain chromatin 

 constituents." 



c. General. 



Index of Vitality.f — Dr. A. D. Waller explains in a very interesting 

 communication that it is possilde to find what we may call an electrical 

 index of vitality — the " blaze " reaction. His best results are with the 

 •eggs of the hen. Whenever " life " is — let us say, whenever metabolism 

 is — in operation, there is this " blaze " reaction, which is absent in con- 

 ditions of latency or mere potentiality. 



Growth of Biology in the Nineteenth Century.J — Prof. O. Hertwig 

 discusses the biological progress of the past century in his usual clear 

 and interesting way. The doctrine of the cell, the study of micro- 

 organisms, the theory of evolution, the experimental method in physio- 

 logy and embryology, the position of biology among the sciences, and 

 the outlook on unsolved problems, ai'e the chief topics of the lecture. 



Fauna of Black Sea.§ — Sir John Murray, in an interesting paper on 

 the deposits of the Black Sea, has some notes on the Fauna. In the 

 denser water there are forms derived from the Mediterranean, through 

 the Sea of Marmora and the Bosphorus, but the lower salinity, the more 

 rigorous temperature, and the presence at a moderate depth of a cold 

 layer, have proved obstacles to abundant migration. Some relics of the 

 glacial epoch, now rare or absent in the Mediterranean, flourish in the 

 Black Sea, e.g. Nodiola phaseolina. Among the shells on the Modiola- 

 mud (35-100 fathoms) there may be found simple Ascidians, two little 

 Ophiuroids, a small Synapta, a few Annelids, Cerianthus vestitus, &c. 

 Below this zone is the domain of hydrosulphuric bacteria. At the mouths 

 of the rivers or " limans " the Mediterranean elements are less numerous, 

 giving place to forms identical or closely allied to those of the Caspian 

 Sea, relics of a pliocene brackish-water fauna. 



Alleged Effect of Lecithin on Growth.ll — Dr. Eugene Wildiers has 

 experimented on tadpoles, chickens, and dogs, and finds that there is no 



* Journ. Boston Soc. Med. Sci., v. (1900) pp. 13-7. 



t Comptes Keudus, cxxxi. (1900) pp. 1173-6. 



X ' Die Kntwicklung d. Biologie im 19. Jahrhundert,' Jena, 1900, 31 pp. 



§ Scot. Geogr. Journ., xvi. (1900) pp. 673-702. 



i| La Cellule, xvii. (1900) pp. 383-407 (1 pi.). 



