6o8 MOSSES AND FERNS 



while each cell of the inner tissue gave rise to a gamete. In the 

 archegonium the fertile tissue formed a single axial row, only one 

 cell of which, the egg, normally was functional. 



Schenck (i) has come to much the same conclusion as Davis, but 

 believes the Archegoniates have come directly from Brown Algae — 

 marine Phaeophyceae. 



In view of the many other obvious points of resemblance between 

 the Archegoniates and the fresh-water Green Algae it is highly im- 

 probable that there should be any genetic connection between them 

 and the strictly marine Phaeophyceas. 



It has been argued by Goebel among other writers, that the arch- 

 egonium and antheridium of the Archegoniates are essentially 

 homologous organs, which would of course agree with the theory of 

 their derivation from some type of plurilocular gametangium. This 

 view is strengthened by work of Holferty (i) and others, who have 

 shown that in certain Mosses structures combining the characters of 

 archegonium and antheridium may occur. 



P. 13. There may be some question as to the desirabihty of 

 removing the Anthocerotaceae from the Hepaticae. Thus Cavers 

 (9), who has made a very careful study of the inter-relationships of 

 the Bryophytes, believes that the differences between the Antho- 

 cerotaceae and the other Liverworts are not sufficient to warrant the 

 establishment of a separate class, but thinks that they merely represent 

 an order of Hepaticae, Anthocerotales, coordinate with the Marchan- 

 tiales and Jungermanniales. 



P. 17. The development of the spermatozoid of the Hepaticae 

 has been the subject of numerous investigations during the past ten 

 years and while there is general agreement as to certain points, 

 there is a decided difference in others. 



In all cases that have been recently examined, the final division of 

 the spermatogenous cells results in the formation of a pair of "sperma- 

 tocytes, " or sperm-cells, which may be separated by a delicate division 

 wall, e.g. Pallavicinia, Calycularia — or the division wall may be 

 suppressed, as in Marchantia and Fossombronia. 



All authorities agree that after the final division into the sperma- 

 tocytes, there is always present a small body, the " blepharoplast, ". 

 but as to the nature of this body, the statements are not at aU in 

 accord. 



Ikeno (4), who studied the spermatogenesis especially in Marchantia 

 polymorpha, believes that the blepharoplast is a centrosome, and that 

 it is of nuclear origin. Schaffner (i) supports this view, but other 



