Development of the Anthendium in Ferns. 237 



Tlic last cx])l;ui;ition of tlic dcvclnjnnont of the fcin-antlio- 

 riiliiim w liich Jlofmcister gives, in the English edition of his 

 * Vcrgleiehende Untersuchungcn'*, does not diflcr essentially 

 from his former one. lie says, "The analogy to be derived 

 from the process of development of the antheridia of the Mus- 

 cinea^ renders it probable that the large central cell is formed 

 by the production of an cxccntrical, inclined, longitudinal 

 septum in the young antheridium, followed l)y the production 

 of another exccntrical septum cutting the latter at right angles, 

 and the subsequent fomiation of a longitudinal septum cutting 

 both the above at an angle of 45°, such formation taking place 

 after the apical cell of the antheridium has been isolated by a 

 strongly inclined, almost horizontal septum cutting the primary 

 longitudinal septum. When the central cell is surrounded by 

 two zones of enveloping cells, it is manifest that the two zones 

 originate in the transverse division of the primary single zone." 



Lastly, Strassburgerf has occupied himself Avith the present 

 subject. In Pteris sernilata, according to him, the mother 

 cell of the antheridium is divided first of all by two oppositely 

 inclined septa, which are set obliquely iq)on the bottom of the 

 antheridium and cut its side walls nearly at their summit. 

 " These first two septa are soon followed respectively by two 

 other opposite ones, cutting them at an angle of 45°. All 

 these lour septa are strongly inclined together towards the 

 base of the antheridium, without, however, absolutely meeting 

 there ; and in this way a central quadrangular space is cut off, 

 which is Avidencd above in a funnel-like form. The upper 

 part of the antheridium is still unicellular ; but a number of 

 diA^isions soon occur in it. First of all, four upper lateral cells 

 are produced in exactly the same way as the inferior ones • 

 they are set u])on these inferior ones, and inclined together 

 towards the apex of the antheridium. Finally, between these 

 upper lateral cells an opercular cell, of the form of the seg- 

 ment of a sphere, is separated from the vertex of tlie antheri- 

 dium. In this way a cellular body is formed, consisting of a 

 central cell, eight lateral cells, and an opercular cell. The 

 central cell, seen from above, is quadrangular, bellied out in 

 the middle of its height, gradually diminished towards its ex- 

 tremities, especially the lower one, and it becomes the primi- 

 tive mother cell of the spermatozoids. It contains an abun- 

 dance of protoplasm and a distinct cell-nucleus, whilst the 

 lateral cells as yet contain only a few chlorophyll-grains." 



* On the Germination, Development, and FructiQcation of the higher 

 Cryptopamia (London, 1862)/p. l8(>. 



t " Die Ikfruchtung bci den Farrnkriiutem," M^m. de I'Acad. de 

 St. Petei-sb. 18G8, p. 2. 



