74 BOTANICAL GAZETTE [januaxy 



illustrated by figs, i, 2, and 3, bore a single crown which was more 

 or less lobed. In section (fig. 19) these lobes proved to be masses of 

 antheridia. The crown on each of the 3 prothallia of L. obscurum 

 (figs. 4, 5) was double. An accident to the sections prevented a 

 study of the relation between the lobes and the location of the sex 

 organs in these prothallia. The crown was unequal in every 

 specimen of L. complanatum and L. obscurum , and the lobes 

 appeared only at one side, as shown in fig. 3. 



The one prothallium of my collection which may cause some 

 readers to question is that of L. lucidulum. I have found 10 

 sporelings and only one prothallium, but this single prothallium 

 fortunately has a sporeling attached. This fact alone would not 

 serve to convince a botanist in doubt of its genuineness. However, 

 there are 5 reasons why I am convinced of its nature. Fig. 9 

 shows these 5 points. They are (1) archegonia, (2) paraphyses, 

 (3) rhizoids, (4) a primary tubercle, and (5) the sporeling arises 

 from it like the sporeling of any recognized gametophyte; there is a 

 foot, and a primary root originates at the point where the stem 

 breaks through. Certainly all these features cannot be connected 

 with a young plant of L. lucidulum of asexual origin or with an 

 associated fungus growth. 



■ 



This prothallium of L. lucidulum, which, like that of L. obscurum, 

 I believe is new to botanists, shows some very interesting evolu- 

 tionary points. The body is somewhat cylindrical, but not entirely 

 so. It is somewhat more flattened longitudinally than the figure 

 shows. In this figure the flat side is turned toward the reader. 

 Near the middle it makes a short twist toward the left. In general 

 outline it looks like a prothallium of L. complanatum in the making, 

 but on the upper lobed region are 4 paraphyses. Such a feature 

 suggests a transition stage between the Phlegmaria type of prothal- 

 lium, as represented by L. Selago, and such a form as L. com- 

 planatum. The specimen contained no chlorophyll so far as I was 

 able to determine. 



Among the 50 sporelings gathered there was a variation in age 

 between 1 and 5 years. Each season's growth above the soil 

 could be determined definitely by the alternate regions of longer 

 and shorter leaves on the species L. clavatum and L. annotinum. 



