160 NATURAL SCIENCE. March, 1895. 



too familiar in scientific writing generally. We are well aware that 

 frequently the invention of new words is a necessity and a gain ; if a 

 new idea has to be expressed, exactness and conciseness may be 

 found only by neology. But what we must insist upon is that the 

 necessity is always a misfortune, and that the neologist, instead of 

 claiming gratitude, should be a suppliant for pardon and should 

 present the fullest excuse. Last month we put the American 

 " letusimulation " in the pillory ; this month the English " isoclero- 

 nomic " and " anisocleronomic " must succeed it. 



In his treatise on the germ-plasm, Professor Weismann ex- 

 panded an idea that he had previously suggested. It is the idea 

 that two kinds of cell-division exist. In the one case the tendencies 

 and characters of the daughter-cells are exactly alike. Each has 

 received an equal legacy from the parent, and, the legacy being . 

 supposed to differ only quantitatively and not qualitatively from the 

 stock of characters that were halved, when the daughter-cells grow up 

 to full stature each becomes an exact replica of the parent. In the 

 other case (the existence of which is not admitted by Weismann's 

 critics), the legacy received by the two daughter-cells differs qualita- 

 tively, the characters and tendencies of the parent are distributed 

 unequally between the daughters, and, when these grow up, each is 

 unlike the other and the parent. These two kinds of division 

 Weismann designated as "erbgleich," "equal-heired," and "erbun- 

 gleich," " unequal-heired " ; but, throwing a sop to esoteric terminology, 

 he called them also " Homoeokinesis " and " Heterokinesis." 

 Professor Hertwig wrote a treatise (of which a full account was given 

 by Mr. Chalmers Mitchell in Natural Science for August, 

 September, and October, 1894) largely devoted to disproving 

 Professor Weismann's hypothesis of the existence of unequal-heired 

 division. Mr. G. C. Bourne, writing in Nature last month a criticism 

 of Professor Hert wig's criticism of Weismann, and agreeing that the 

 existence of the two kinds of division has not been established, 

 invents the new names for them isocleronomic and anisocleronomic, 

 overlooking, first, that we might have the fact before the name ; 

 secondly, that the German name and its English equivalents are 

 ample ; thirdly, that if Greek be necessary the original inventor has 

 already suggested Greek names. 



