and its relation to that in the Animal Kingdom. 451 



Whether or not the suspensor of the Coniferse, which gives 

 origin to a number of embryos, is to be regarded as a nurse (Amme), 

 cannot be decided from the varying statements of authors, nor, 

 indeed, until we obtain perfectly continuous series of observa- 

 tions on the stages of development of the Coniferse. The phse- 

 nomenon in question would in such case assume a great pecu- 

 liarity, beyond its early occurrence, from the fact that, since only 

 one of the numerous embryos actually becomes developed, — 

 asexual multiplication of a sexually generated individual in truth 

 never taking place, — it would represent little more than an at- 

 tempt {sit. ven. verb.) at alternation of generations. 



The antheridial granules of the Selaginellaj and Rhizocarpese 

 constitute the most direct transition imaginable between the 

 pollen-grains of the Phanerogamia and the antheridial cells (of 

 an early rank — the mother-cells of the cells producing the sper- 

 matozoids) of the Equisetaceaj and the Ferns (in the restricted 

 sense). While they correspond with the former completely in 

 reference to their origin and formation, and even in the earlier 

 features of their subsequent development — the emergence of the 

 internal cell out of the cuticle in the form of a tube, — they agree 

 with the latter in the ultimate formation of definitely shaped 

 fecundating elements inside special vesicles. An immediate ap- 

 proximation to the last process is met with in the pollen-tubes of 

 the Coniferse, in the occurrence of a distinct cell-formation. 



If, led by the unmistakeable analogies which the Coniferse 

 exhibit, on the one hand with the Phanerogamia, and on the 

 other with the Lycopodiacese and Rhizocarpcie, we have found 

 the right path to the explanation of the import of the fecundating 

 organs in the Ferns (in the wider sense), we shall hardly allow 

 ourselves to be diverted from it again, although in the lower sec- 

 tions of this group, the Equisetacea and Ferns propei', we may 

 find these organs no longer rigidly preserving their original resem- 

 blance. We find the germinal vesicle, central cell of the arche- 

 gouium, and the arehegonium itself, here still true to the former 

 type. Only the organ bearing the latter, the female receptacle, 

 the protliallium, undergoes striking metamorphoses. These relate 

 above all to its size, shape, and its relation to the cell (spore) 

 giving origin to it; more remotely they result from the neces- 

 sities of an independent nutrition (formation of radical fibrils). 

 In the male fecundating organs also we here find diversities 

 connected both with their organization and their position. We 

 have already referred to the former ; in regard to the latter, we 

 here no longer find the antheridia connected with the morpho- 

 logically developed plant, but transplanted, either alone (uni- 

 sexual flowers), or together with the archegonia (hermaphrodite 

 flower) on to a prothalli\uii. If we understand by the term 



29* 



