THE ARCHEGONIAT^E 



213 



the Anacrogynse, like Blasia and Symphyogyna (Fig. 172, E), show 

 a development of rudimentary leaves, or special assimilatory organs, 

 like those which characterize the more specialized Acrogynae. 



Anelatereae. The simplest of the Anacrogynae are the Anelaterese, inter- 

 mediate in some respects between the typical Anacrogynee and the Ricciaceae, 

 which they resemble somewhat in the apical growth of the thallus and the char- 

 acter of the sexual organs. The genus Sphaerocarpus (Fig. 160) is, on the whole, 

 the lowest of these. Riella, and the monotypic Geothallus of Southern California 

 (Campbell, 3), are the other genera. The Anelatereae are so called because the 

 sterile archesporial cells do not develop into perfect elaters, but remain as 

 oval, thin-walled cells, usually containing starch and some chlorophyll. In 



FIG. 172. A, Aneura (Riccardia) pinnatifida (X 4). B, Pallavicinia cylindrica 

 (X 2). C, D, Fossombronia longiseta (X 3) ; sp., ^porophyte. E, Symphyogyna, 

 sp. (X lj). ?, archegonial receptacle. F, Bazzania sp. (X 2). 



the typical Anacrogynae (e.g. Pellia, Aneura, Fossombronia, etc., Fig. 172) 

 the reproductive organs are borne, singly or in groups, upon the dorsal surface 

 of the thallus, or that of special branches. The archegonium is much like that 

 of the Marchantiales, but except in the lowest forms, there are but five peripheral 

 cell-rows in the neck. The antheridium (Fig. 173), however, is quite different, 

 and agrees with that of the Acrogynae. The first division-wall in the upper part 

 of the antheridium is vertical and divides it equally into two cells, in which 

 the next divisions separate a central cell from three peripheral ones, so that the 

 antheridium consists of two central cells which subsequently give rise to the 

 sperm-cells and six peripheral cells, which produce the wall. The spermatozoids 

 are relatively larger, and coiled several times. At the anterior end are two very 

 long cilia. 



The root-hairs of the Jungermanniales are always of the simple 

 type, and the scales found upon the ventral surface of the Marchan- 

 tiales are replaced in these forms by glandular hairs, which serve to 

 protect the growing-point of the shoot. 



