294 Lang . — The Prothallus 
No perforation in the wall has been seen in any specimen, and 
it is quite possible that the contents of these dilatations of 
the mycelium are absorbed in the same way as from the 
filamentous portion. On the other hand, it is not impossible 
that in some instances at least the contents may escape into 
the cell-cavity. In this connexion another characteristic of 
the region of mycorhizal tissue in which the vesicles are 
mostly empty must be referred to, although its significance 
is still doubtful. There are frequently to be found in the cells 
of this region small round or oval bodies, the walls of which 
stain deeply with Bismarck-brown ; a cell containing these 
spore-like bodies is represented in Fig. 34. They may be 
distributed through the mycelium, with which they sometimes 
appear to be connected, or may form a more or less compact 
group. Though appearances suggestive of an origin of these 
‘ spores ’ from the contents of the multinucleate vesicles have 
been seen, it has been found impossible to demonstrate any 
connexion between the two structures. The question must 
therefore be left open. In the case of prothalli the marginal 
growth of which had ceased, the changes described above as 
affecting the older mycorhizal cells extend to those close to 
the margin until in these also the contents of the hyphae have 
disappeared ; the nuclei and protoplasm of the vesicles persist 
longer. 
The multinucleate vesicles described above appear to be 
the same as the ‘ Sphaeromen 5 described by Bruchmann 1 in 
the prothallus of this and other species of Lycopodium. The 
considerable differences between the above description and 
that given by Bruchmann may be accounted for by the fact 
that the methods employed in the present investigation have 
demonstrated the contents of these bodies more clearly. 
They appear also to agree closely with the ‘ vesicules 5 found 
by Janse 2 in a large number of examples of mycorhiza. The 
organs of the endophyte, termed by that author ‘ sporangioles,’ 
1 Bot. Cent., xxii. 1885, p. 312, and loc. cit., 1898, pp. 19 and 23. 
3 Annales du Jard. Bot. Buitenzorg, xiv. p. 53. 
