THE A M ERIC AN NA TURALIST. [Vol. XXXV 1 1 . 



the Eusporangiatae, is also very massive, and as far as possible 

 from any known algal form. Of course in the Ophioglossaceae, 

 the saprophytic nature of the gametophyte has doubtless to some 

 extent modified its structure. 



The archegonia of the Marattiaceae are extraordinarily like 

 those of the Anthocerotaceas, and the antheridia also offer cer- 

 tain suggestions of a similar origin to those of the latter order. 

 Indeed, were it not for the biciliate spermatozoids of the Antho- 

 cerotaceae, and their peculiar chromatophores, I should not hesi- 

 tate to assume a direct connection between the latter order and 

 the eusporangiate ferns. 



The extraordinary uniformity in both structure and develop- 

 ment of the archegonium throughout both Bryophytes and 

 Pteridophytes, including such a marked character as the ventral 

 canal-cell ; the great similarity in the origin and development of 

 the spermatozoids, and the details of fertilization, certainly are 

 very strong arguments for a common origin for all Archegoniates. 

 The theory that these resemblances are merely parallel develop- 

 ments can only be accepted on the production of very much 

 weightier evidence than has yet been brought forward. 



When to the obvious resemblances existing between the game- 

 tophytes of the ferns and liverworts (of course the lower types 

 . like the anacrogynuus Jungermanniales and the Anthocerotaceae 

 being understood) there are added the numerous resemblances 

 in the development of the sporophyte, the probability of a genetic 

 connection between the two phyla of the Archegoniates becomes 

 enormously greater. The fallacy of Dr. Scott's argument, that 

 the assumption of the antithetic theory involves the creation of 

 a structure de novo, without any apparent ancestry, has been 

 perfectly refuted by Professor Bower. There is no claim that 

 the sporophyte is an entirely new structure. It starts with the 

 zygote, which on germination produces a greater or smaller 

 number of spores, thus increasing the number of plants result- 

 ing from a single zyg< >te, an < >bvi< >us advantage. The rudimentary 

 sporophyte of Coleochaste, which there is no difficulty in homol- 

 (i--i/ing with the zygote-product of CEdogonium, may equally well 

 be compared with the sporophyte of Riccia, as has often been 

 done, whether we assume that the sporophytes of the two are 

 genetically related or not. 



