21 



Regarding the much flattened stem and suppression of the 

 under leaves as indicating the amount of dorsiventrality, it would 

 appear that Professor Goebel is quite right. It was, however, 

 not in this sense that I used the expression, for I referred rather 

 to the remarkable amount of difference in the form of the leaves 

 which are indeed trimorphic, a matter which has been sufficiently 

 elucidated in the paper above alluded to. It would seem, there- 

 fore, that Lycopodium alpinum occupies a peculiar position, and 

 may more properly be regarded as a parallel species with L. com- 

 planatwn. The two species represent two different kinds of special- 

 ization and the peculiar features of the plant L. alpinum may 

 perhaps be due to an attempt to revert to a radially symmetrical 

 condition, a suggestion prompted by the fact of the orthotropous 

 position of the branchlets above referred to. 



Lycopodium Selago L. — The brood bodies or gemmae of 

 Lycopodium lucidulum Michx. are produced on curiously modified 

 branches, which do not, as many suppose, develop in the axils 

 of leaves. It is not very widely known that some, the proximal, 

 leaves of these peculiar branches are so modified as to form .a 

 mechanical apparatus for the expulsion of the distal part of the 

 shoot, which constitutes the brood body. 



I have been fortunate in extending this observation to Lyco- 

 podium Selago, which was found growing in the alpine regions 

 of the mountains in the vicinity of Brenner. Observation shows 

 that a very light touch is sufficient to release the mechanism 

 which acts as a pinching catapult, if we may so call it, and may be 

 compared to the somewhat similar mechanical condition seen in 

 the dehiscent fruits in Viola and Hamamelis. The gemmae are 

 cast to a distance of several centimeters, sometimes ten or more. 



Undoubtedly the same will be shown to occur in Lycopodium 

 porophilum Lloyd & Underwood. 



Teachers College, Columbia University. 



