iqiqI BASSLER—SPORAKGIOPIIORICLEPIDOPHYTE 91 



homologous. The outer field of the sporangiophore of Canthe- 

 liophorus might then be represented in the 2 species of Calamostachys 

 just considered by the plate of sterile tissue above the sporan- 

 giophore, and the guard in one case, which is peltate with respect 

 to the brace considered alone, would then become the homologue 

 of the peltate extremity of the sporangiophore in the other. 



The sporangiophore of Calamostachys Decaisnei Ren. which we 

 have reproduced is inclined slightly toward the bracts beneath it. 

 This may be accidental, but with just a little more inclination, 

 together with the closing of the space between it and the bracts 

 below by a sterile plate (of which we already see some development) , 

 we should have a sporangiophore almost precisely like that of 

 Cantheliophorus. With coalescence, further, of the pair of sporangia 

 upon each side of it and the concrescence of the 2 subjacent bracts, 

 we should have to all outward appearances Cantheliophorus itself. 

 Whether or not there are two parallel vascular bundles in the mid- 

 rib of the blade of Cantheliophorus as possible evidence of such a 

 history we have at this time no means of knowing, but we may 

 recall with some interest in this connection that a species of Sigil- 

 laria from Autun does bear a leaf with 2 vascular bundles in the 

 midrib, and it seems significant that in general the stem anatomy 

 of this species closely resembles that of 5. Menardi, which of all 

 the known Lycopods is perhaps closest to the Calamites in this 

 respect, as I have shown elsewhere in this paper, and according 

 to the theory here set forth one of the most primitive. It was 

 Renault (20) in 1879 who described this species under the name 

 of Sigillariopsis Decaisnei. 



It may be well in passing to remind our readers that according 

 to the theory here proposed the sterile plates within the sporangia 

 of Lepidostrobus were not developed, as Bower suggested, primarily 

 to serve for the nourishment of the spores, but it is probable that 

 they did well serve that purpose in a sort of secondary or incidental 

 manner, transferring nourishment to the interior of the sporogenous 

 mass in the early stages of its development, and finally wasting 

 as they yielded their own substance to the developing spores. 



There is yet one weakness (8) in this theory of the descent of 

 the Lycopods. "It is not enough to suggest reduction on mere 



