538 THE NATUEAL KISTORY BEYIEW. 



that the ascigerous form of perithecium is developed from the 

 spermatiferous form. »]ffiJob i: 



The third form of perithecium to be considered, is C. the transi- 

 tional form. 



This sometimes resembles form A. and sometimes form B. It 

 contains a number of paraphyses of all sizes, and a crowd of free 

 spermatia. The paraphyses are shorter at the upper part of the 

 perithecium, and at the apex of it resemble the spermatiferous threads. 

 M. Sollmann is of opinion that these threads become by a terminal 

 and peripheral increase in growth, transformed into paraphyses. 



The asci are situated between the more advanced paraphyses. 

 The largest asci are more or less filled with spermatia, the younger 

 ones hardly project above the fructifying layer. The cavity of the 

 young ascus is continuous with that of the mother-cell. The parts 

 of the fructifying layer upon which the asci are formed, are full of 

 spermatia, which lie partly on, and partly e??- the cells. The spermatia 

 which are in the mother- cells pass upwards into the interior of the 

 young ascus. Ultimately the ascus (which has become clavate) is 

 quite stuffed with spermatia, and becomes opaque. The cavity of 

 the ascus is now divided from that of the mother-cell, and no further 

 entry of spermatia can take place. 



v: M. Sollmann then proceeds to describe the process of fructifica- 

 tion {Befruchtungsact). He says that eight membraneless bodies 

 (cytoblasts) are developed in the ascus, either by free cell formation, 

 or by division, but probably by the former. These bodies have a 

 smooth surface, and become elongated in the direction of the longi- 

 tudinal axis of the ascus. Thus they become first roundly elliptical, 

 and at last elongate- elliptical. Up to this time they have no spiral 

 membrane. At this stage the spermatia attach themselves by one 

 end firmly to the surface of the cytoblasts. At the point where the 

 spermatium attaches itself, the surface of the young spore gradually 

 disappears, and the pole of the spermatium thus at lasts comes into 

 contact with the contents of the spore. The spermatia come from 

 all directions, and attach themselves firmly all over the surface of the 

 young spore. The portion of the spermatium which penetrates the 

 spore remains visible within it for a considerable time. 



Ultimately the spermatia make their way into the spore, and the 

 edges of the openings through which they have entered unite, leaving 

 the surface of the spore with slight elevations at the points of entry. 

 As the spermatia get deeper into the spore, these elevations dis- 



