LITERATURE 287 



The existing contradiction of results has led to the opinion, expressed 

 by a number of recent writers, that the difference between longitudinal 

 or transverse division is of minor importance, and that the entire 

 question of reduction is a barren one. This opinion fails to reckon 

 with the facts on which rests the hypothesis of the individuality of 

 chromosomes (Chap. VI.); but these facts cannot be left out of 

 account. We must find a common basis of interpretation for them 

 and for the phenomena of reduction ; yet how shall we reconcile 

 them with reduction by longitudinal division only } I cannot, there- 

 fore, share the opinion that we are deahng with a barren problem. 

 The peculiarities of the maturation-mitoses are obviously correlated 

 in some way with the numerical reduction, and the fact that they 

 differ in so many ways from the characters of ordinary mitosis gives 

 ground to hope that their exhaustive study will throw further light ^ 

 not only on the reduction-problem itself but also on mitosis in general 

 and on still wider problems relating to the individuality of the chromo- 

 somes and the morphological organization of the nucleus. It is indeed 

 very probable that Weismann's theory is but a rude attempt to attack 

 the problem, and one that may prove to have been futile. The prob- 

 lem itself cannot be ignored, nor can it be dissociated from the series 

 of kindred problems of which it forms a part. 



LITERATURE. V ^ 



Van Beneden, E. — Recherches sur la maturation de Toeuf, la fecondation et la division 



cellulaire: At-ch. Biol, IV. 1883. 

 Boveri, Th. — Zellenstudien, I., III. Jena, 1887-90. See also " Befruchtung " 



(List IV.). 

 Brauer, A. — Zur Kenntniss der Spermatogenese von Ascaris 7negalocephala : Arch. 



mik. Anat., XLII. 1893. 

 Id. — Zur Kenntniss der Reifung der parthenogenetisch sich entwickelnden Lies von 



Artetnia Salina: Arch. ?fiik. Anat., XLIII. 1894. 

 Guignard. L. — Le developpement du pollen et la re'duction chromatique dans le 



Naias: Arch. Anat. Mic. II. 1899. (Full literature on reduction in plants.) 

 Griffin. B. B. — See Literature. IV. 

 Hacker. V. — Die \'orstadien der Eireifung (General Review) : Arch. mik. Anat., 



XLV. 2. 1895. 

 Id. — Uber weitere Ubereinstimmungen zvvischen den Fertpflanzungsvorgangen der 



Thiere und Pflanzen: Z)'/W. C^;//';-fl'/^.. XVII. 1897. 

 Id. — Uber vorbereitende Theilungsvorgange bei Thieren und Pflanzeri : Verh. 



deutsch. Zoo!. Ges., VIII. 1898. 

 Id. — Die Reifungserscheinungen : Mcrkcl iind Bonnefs Ergebnisse. VIII . 1898. 

 Hertwig, 0. — Vergleich der Ei- und Samenbildung bei Nematoden. Eine Grund- 



lage fiir cellulare Streitfragen : Arch. mik. Anat., XXXVI. 1890. 

 Mark. E. L. — (See List IV.) 

 Peter, K. — Die Bedeutung der Nahrzellen im Hoden : Arch. 7nik. Anat., LIII. 1898. 



1 See also Literature, IV., p. 231. 



