1920] SMITH— BULBILS OF LYCOPODIUM 427 



were distinguishable by their greater size. My observations on 

 this feature agree with Hegelmaier's. I have not been able, in 

 longitudinal sections, to distinguish a young bulbil from a young 

 leaf until it is recognizable by the beginning of an apical meristem 

 at its tip. Strasburger discussed the homology of the bulbil 

 with considerable care, and after considering the possible explana- 

 tions concluded that all the facts of development and histology 

 are best combined in the supposition that the bulbil represents 

 the survival of an original dichotomy ("eine einst dichotomischen 

 Ursprung"). 



Much the same interpretation is given by Campbell (i), who 

 says the bulbils "are formed apparently in the axils of somewhat 



modified leaves The axillary origin of the bulbils is only 



apparent; they are really, so far as can be determined, similar in 

 origin to ordinary branches and formed without any relation to 

 the leaves." 



Goebel (3) considered the bulbils from the point of view of 

 their adaptations rather than their homology. Although dis- 

 claiming any attempt to solve the latter, he brought forward some 

 pertinent objections to current morphological explanations, and 

 concluded that in their most important features the bulbils of 

 Ly co podium are not unlike the bulblets of certain species of Allium 

 and Lilium. 



The present investigation is an attempt to help solve the problem 

 of the bulbils by means of modern technique and serial sections 



1 



which were not available to the earlier investigators. Only L. 

 lucidulum has been studied, suitable material of other species not 

 being obtainable. Strasburger, however, found that there is a 

 great similarity in the bulbils of the six species which he compared, 

 and it is probable therefore that the following account with only 

 minor changes will hold good for all. 



Description of bulbils 



Two parts must be distinguished in the bulbil: the base which 

 remains attached to the stem of the plant for many years and does 

 not store up nutriment; and the distal part, or bulbil proper, which 

 is heavily laden with starch grains, and which, when mature, 



