SEXUAL ORGANS OF PELLIA 



235 



side. The sperms, very many of which are produced 

 in each antheridium, are not unlike those of Volvox 

 in shape, and like them have two flagella, but there 

 is no trace of a chloroplast, and the long, narrow, 



Fig. 37. — Pellia. A, part of cross-section of thallus, showing ripe 

 antheridium; w, wall of antheridium; spe., sperms (male) gametes 

 coiled up. X 80. B, single male gamete (after Guignard, 

 X 122). C, four archegonia in various stages of development. On 

 the left the archegonium is nearly ripe ; w, wall of venter con- 

 taining egg ; n, neck, which will shortly open at the top. D, group 

 of multicellular spores (spo.) with spirally thickened elaters {el.). 



