348 THOS. H. MONTGOMERY, 



If there were not already beforehand a continuous linin spirera, 

 how could we explain the arrangement of the chromatin into a single 

 thread, such as occurs in many prophases? 



This puts the idea chromosome into a somewhat different light 

 from that generally assumed, and hence also the question of the 

 persistence and individuality of the chromosome. As has been shown, 

 in Peripatus from the prophase of the last spermatogonic mitosis up 

 to the monaster of the 1st maturation division, a continuous linin 



in Ascaris. Gtilson (1889, cited by Hacker, 1895; I have not seen 

 Gilson's paper) found a continuous spirem in resting gland cells of 

 Slaps. And Van Gehuchten (cited also by Hacker, 1. c.) described 

 the same structure in the larva of Ptychoptera. Hermann's (1889) 

 figs. 15 and 16 represent prophases in the 1st maturation division 

 of Salamandra, and from the ends of the chromosomes go out linin 

 fibres which would seem comparable to my distal linin threads. Vom 

 Rath (1892) in describing the prophase of the 1st maturation division 

 of Gryllotalpa, states: "Es sind aber nun nicht nur je vier Chromo- 

 somen mit einander durch Linin verbunden, vielmehr sieht man feine 

 Lininfäden .... zwischen den Chromosomen verschiedener Gruppen 

 verlaufen, so dass sämmtliche Chromosomen in einem gewissen Zu- 

 sammenhang stehen " Rückert (1894) could not determine 



in the maturation of Copepoda whether the chromosomes persist 

 separately or whether there is a continuous linin spirem joining them : 

 "Wohl kann man oft feststellen, dass die Chromosomen sich in blasse 

 oder ungefärbte Bahnen fortsetzen und dass sie auf diese Weise mit 

 andern gefärbten Fadenstrecken vereinigt sind, aber ob dies durch- 

 gehends der Fall ist, lässt sich nicht sagen .... theoretische Gründe 

 scheinen dafür zu sprechen, dass auch hier die Chromosomen nicht 

 völlig unverbunden sind.'' Born (1894) in his work on Triton states: 

 "Die ganze Chromatinstructur behält aber während der ganzen Aus- 

 bildungsperiode des Eies die einmal angenommene Knäuelform, so dass 

 es nach Beendigung der Ausbildung des Eies nur einer Verdichtung 

 bedarf, um den (secundären) Chromatinfadenknäuel wieder herzustellen, 

 der dann in die Mitose eintritt." Hacker (1895) finds in the prophase 

 of the 1st maturation mitosis of Canthocamptus^ that the chromatin 

 segments may separate from one another, but still remain connected by 

 linin, and hence holds that the spirem persists through the stages of 

 the germinal vesicle ; and he had "in den grossen Kernen des Wimper- 

 reifes einer Polychätenlarve {Folyno'é) eine Anordnung des Chromatins 

 in langen Fadenzügen beobachtet". Wilcox (1895) described for 

 Caloptenus that in prophases of the 1st maturation division "the 

 chromatic granules gradually become collected at twenty-four points on 

 the thread. The thread then breaks transversely into twelve segments" ; 

 but several of his figures would indicate that the chromosomes in later 

 prophases are arranged along a continuous linin spirem. 



