XIV L YCOPODINE^E 465 



which Trcub refers probably to the i^ciuis Pythiuiii. We have 

 seen that similar fungus mycelia occur in the chloroi)hylless 

 prothalliuni of Juitryr/ii/iiii, antl Goebel f(juiul the same in L. 

 inundatiiiii. While in the primary tubercle the fun!_,ms occupies 

 the lumen of the cells, as it penetrates into the body of the 

 prothallium it confines itself mainly to the intercellular spaces, 

 where its growth causes more or less displacement of the 

 cells. It does not, however, seem to penetrate into the meri- 

 stematic tissues at the summit. 



The fully-grown prothallium of L. cernuiivi is a small upright 

 cylindrical body, seldom, apparently, exceeding about two mm. 

 in height. The base is more or less completely buried in the 

 ground, and contains but little chlorophyll. The summit is 

 surrounded by the lobes already spoken of, and these have 

 somewhat the appearance of leaves crowning a short stem. The 

 whole structure of the prothallium recalls in some respects that 

 of Equisetuui^ and like that resembles the young plants of 

 Antlioceros fiisiforinis or A. pwtctatus. 



Besides the type of prothallium found in L. cermium, with 

 which L. immdatum closely agrees, Treub has also studied the 

 very different pi^thallium of L. phlegvim'ia, and others of similar 

 habit. These are only known in their mature condition, in which 

 they are saprophytes, growing in the outer decayed layers of 

 bark upon the trunks of trees. In this condition they are 

 extremely slender branched structures, totally different from 

 those of L. cernuuui, both in form and in the complete absence 

 of chlorophyll. Like the prothallia of many Hymenophyllacea;, 

 they multiply by special gemmae and apparently may live for 

 a long time. Like those of L. cernuum they are always infected 

 by an endophytic fungus. 



A third type of prothallium is that of L. annotinum, which 

 is also destitute of chlorophyll in its adult condition, but is com- 

 pact in form, more like that of Botrycliiuvi. Unfortunately in 

 this species, as well as the PJdegniaria type, the germination of 

 the spores is unknown, and it is still doubtful whether chloro- 

 phyll is developed at first, as in L. cernmivi. 



T/ie Sexual Organs 



The prothallia of all the forms investigated are monoecious, 

 and the sexual organs not arranged in any definite order. 



2 H 



