362 Dr. II. E. Ziegler on Amitotic Nuclear Division 



ostrurn, with antenrial spines and with an arched median, 

 dorsal, spiny crest on the gastric region. There is no trace 

 either of eyes or even of eye-peduncles. First and third 

 pairs of legs of the usual Crangonine form ; second pair non- 

 chelate, rather robust, with fringes of long plumose setJB, 

 their dactylopodites minute, setulose ; third and fourth pairs 

 rather more robust than, but siaiilar to, the second, with 

 successively more minute and less gressorial dactylopodites, 

 also furnisiied with long fringes of plumose setfe. Abdomen 

 compressed, smooth, transversely convex, without spines or 

 cariiiic. Telson thin and depres-t^ed. 



34. Prionocrangon ommatosteres, sp. n. 



The serrated gastric crest is seven-toothed. 



The animal measures in length, from tip of rostrum to tip 

 of tels(in, about 30 niillim., of which the carapace from tip of 

 rostrum to middle of hinder margin is about 10 millim. 



A single somewhat mutilated sj)ecimen from Station 116, 

 405 fathoms. 



[To be coutiuued,] 



XLVIIt. — l^ke Biological Import of Amitotic [Direct) Nuclear 

 Division in the Animal Kingdom. By H. E. Ziegler, 

 Ph.D., Extra-ordinary Professor of Zoology, Freiburg 

 i. B. * 



In W. Flemniing's most recent paper f we find the following 

 passage : — " As regards the fragmentation of the nuclei of 

 leucocytes — and amitotic nuclear division in general — it 

 appears to me not impossible that the following view could 

 also be held. The leucocytes, like the cells of other tissues, 

 perform their normal physiological reproduction by means of 

 mitosis ; those cells only which have come into existence by 

 this process preserve the faculty of continuing to live and of 

 producing simihir cells in the same manner. Fragmentation 

 oj the nucleus^ xoith and without subsequent division oftheceU^ 

 is universally a proctss in the tissues of Vertebrates^ which 



* Translated from the ' ]?iulogisclies Ceutrulblatt,' Bd. xi. nos. 12 and 

 13, pp. 372-380, July 15, If^Dl. 



t W. Flemming, " Ueljor Teiliing- iind Keriifonnen bei Leiikooyteu and 

 iiber dereii Attraktionsspharen,'' Arcliiv f. niikr. Anatomie, 37 Bd., 1891. 



