LE DÉVELOPPEMENT DU PÉRITHÈCE 191 



observation can be made out to be due simply to superpo- 

 sition. Some cases cannot be cleary determined. The 

 nuclei are so smail and the amount of stainable substance 

 in them is so inconsiderable, being especially marked 

 owing to the stained protoplasm, rendering them compa- 

 ratively transparent and therefore almost indéterminable 

 in regard to their boundaries, that a positive statement 

 as to fusion in such cases cannot be given. Nevertheless 

 it is highly probable that fusions occur. There is an 

 indoubted fusion between the antheridial branch and the 

 young ascogonium, the extent of the fusion never being 

 mucli greater than will permit of the passage of nuclei. 

 That nuclei do pass from one organ to the other at some 

 period is certain, since they bave been found in the com- 

 municating canal. The fusion always takes place prior 

 to the formation of the wall across the archegonium, 

 which cuts off the central cell, so that the inference is 

 that a nucleus or nuclei passed from theanteridiai branch 

 into that région of the ascogonium before the formation 

 of the wall. 



« Probablymany nuclei pass, since, after the central cell 

 is eut off, it is found to becrovvded with nuclei, while the 

 number of nuclei in the antheridial branch seems to be 

 less than in rather younger branches. Having admitted 

 the extrême likelihood of tho course of events up to this 

 point, supported as they are by direct observation, by 

 every analogy it follows that the maie nucleus or nuclei 

 fuse with female nuclei in pairs in the central cell. The 

 absence of one or two specially large or conspicuous 

 nuclei supports the view that numerous fusions occur. The 

 time of the occurence of the fusions is probably during the 

 State of aggregation of nuclei at the centre of the central 

 cell, when it is beginning to swell. » 



Tout ce passage montre combien l'auteur était indécis 

 au sujet de l'existence des fusions nucléaires, malgré tout 



