1917] SPESSARD—PROTHALLIA OF LYCOPODIUM 71 



arises straight out of the end lying immediately beneath the 

 surface of the soil. The habit of growth cannot be stated defi- 

 nitely for L. obscurum and L. complanatum. The specimen of 

 L. complanatum shown in fig. 3 was found in the same position as 

 the specimen of L. obscurum shown in fig. 13. All the other 

 specimens of L. obscurum and L. complanatum which I collected 

 were disturbed before I saw them, and consequently their exact 

 position was not determined, except the one in fig. 1 which grew 

 vertically. In size, the prothallia of figs. 4 and 5, are very similar 

 to that of fig. 13. This resemblance in size, together with a common 

 external contour, are my only reasons for assuming that these 3 

 specimens belong to the same species. But here arises a difficulty. 



mm m 



mm 



find the two growing in exactly the same position. This may 

 mean two things; either the prothallia I have classed with L. com- 

 planatum , except no. 1, might as readily belong to L. obscurum , 

 or the prothallia of L. complanatum grow in various positions in 

 regard to the directions of their axes. If the axis of a prothallium 

 of L. complanatum can be shown to grow always in a vertical 

 position, and if that of L. obscurum can be shown to grow always 

 in a horizontal position, the identification of the two species will 

 then become a very simple matter if care be taken w r hile hunting 

 for them. I can only regret that this important point must be 

 left for future observation to settle. 1 



Adult sporophytes of L. cfavatum and L. annotinum were rare 

 in this immediate locality, only one small patch of each having 

 been found. A few plants of L. complanatum were found. L. 

 obscurum and L. lucidulum grow in small clumps throughout the 

 region. 



The 50 sporelings belong mainly to L. clavatum, but a few were 

 found of all the other species mentioned in this paper except 

 L. complanatum. Since the sporeling is the first guide in the 



x On November 5, 19 16, after this paper had gone to press, the writer found a 

 large specimen of L. obscurum with sporeling attached. It was of the same color 

 and shape as and grew horizontally like the prothallium labeled L. complanatum in 

 fig. 3. This bears out the suggestion that all the prothallia classed with L. com- 

 planatum, except no. 1, very probably belong to L. obscurum. 



