ON THE DEVELOPMENT OF LICHENOPORA VERRUCARIA. 127 
production of testes did really follow some definite law. The 
only general statements that I can make are to the effect that 
testes may be present during any of Stages A—G; but that 
while they are normally present in the younger stages they 
are much less common in the older ones. Thus of nineteen 
colonies in Stage F, in which I have noted this particular 
point, seven had well-developed testes, while twelve had none 
at all, or only slight remains. In some cases in which no 
functional testes occur in the colony, the former presence of 
these bodies can be proved by the presence of their degenerat- 
ing remains in the recently formed brown bodies. Of ten 
colonies in Stage G, in which I have noted the presence or 
absence of testes, only one had well-developed male organs; 
while in nine none were present, or at most the last remains 
of testes which had previously been active. 
This seems to indicate that the energies of the colony are 
given as much as possible to the production of embryos during 
Stage G, and the development of spermatozoa is meanwhile 
suppressed. 
It has already been pointed out that the healthy development 
of the embryos is dependent on the functional activity of the 
polypides. Were these to degenerate to any great extent 
during Stage G, it is probable that the development of the 
embryos would be interfered with. This is borne out by the 
examination of various colonies in which degeneration is 
actually taking place, and even more strikingly by the character 
of certain colonies in which the embryonic development has 
clearly been modified by conditions of insufficient nutrition. 
These are colonies in which all or most of the polypides have 
degenerated. The ovicell should be in Stage G, and it has 
actually succeeded in producing perhaps three to six mature 
embryos. But instead of finding the ovicell crammed with 
embryos of all ages intermediate between these and the youngest 
secondary embryos, the ovicell contains nothing in addition to 
the mature embryos except a very few small fragments of 
embryonic tissue. It may be concluded that these are not 
colonies in which the production of secondary embryos is 
