THE AMERICAN NA TURALIST. [Vol. XXXVII. 



highly developed chlorophyll-tissues, and the central strand of 

 conducting tissue, apparently the true homologate of the primary 

 vascular bundles of the Pteridophyte embryo, are certainly sug- 

 gestions, if not forerunners, of the corresponding pteridophytic 

 structures. To my mind there is far less difference between the 

 sporophyte of such a simple Pteridophyte as Ophioglossum or 

 Phylloglossum and that of Anthoceros, than there is between the 

 latter and Riccia. 



When Professor Coulter, for example, says, "In contrasting 

 the sporophytes of Bryophytes and Pteridophytes, they seem to 

 have nothing in common except that they are usually derived 

 from the oospore and represent an asexual generation," we feel 

 that the question has not been fairly stated. As we have tried 

 to show, the sporophytes of the higher Bryophytes and Pteri- 

 dophytes agree closely in the following important particulars: 

 The early divisions of the embryo ; the development of a special 

 absorbent organ, the foot, thus inaugurating the terrestrial habit 

 of the sporophyte ; the gradual subordination of the spore-func- 

 tion, and even an approach to the formation of sporangia in 

 Anthoceros ; the development of special chlorophyll tissue and 

 in some cases of an assimilative organ, the apophysis ; the devel- 

 opment of special conducting tissue ; and finally the absolute 

 identity in the character and formation of the spores, with the 

 characteristic reduction in the number of chromosomes. These 

 may be all mere parallel developments, and not genuine homolo- 

 gies ; but it will require a great deal of direct testimony to make 

 this in the least degree probable, especially when to these obvious 

 resemblances in the sporophyte are added the equally remarkable 

 correspondences in the structure of the gametophyte of the 

 liverworts and ferns. 



Again, when Professor Coulter says that the sporophyte of 

 the Bryophytes never develops lateral members, and has nothing 

 comparable to sporangia, his statement is open to question. 

 While the complicated apophysis of a Polytrichum or Splachnum 

 may not be strictly an appendicular organ, it may assume a 

 flattened, leaf-like form in S. luteum, comparable to a perfoliate 

 leaf, and is as truly a photosynthetic organ at least in its younger 

 condition, as is the leaf of a fern. Of course I do not mean to 



