ON THE DEVELOPMENT OF LICHENOPORA VERRUCARIA. 105 
to the primary polypide-bud of a zocecium which is younger 
than z* and z°, since no brown body could be detected in it. 
A precisely similar egg occurred in another polypide bud of the 
same age in the same colony. 
Fig. 16 shows part of the polypide of z? of a rather long and 
narrow colony, measuring ‘48 mm. in length. The first three 
zocecia are fully formed; and each has a brown body, a poly- 
pide, and a testis. z! has either one or two eggs, and z? has 
the two eggs shown in the figure. I have observed in all six 
cases in which eggs were developed in z!, and in one of these 
the egg was found in the recently formed brown body. It 
appears to me that z! may occasionally give rise to true eggs ; 
but I have observed no single case in which an embryo is 
formed in that zoecium. It is probable that the eggs shown 
in fig. 16 would (one or both) have developed, and that the 
zocecium (z°) which contains them would have become fertile. 
In another case the zocecia of a comparatively old colony 
had formerly contained brown bodies and polypides. All the 
latter had, however, degenerated (probably simultaneously), 
forming a series of recent brown bodies, in which the remains 
of testes can be detected. Each zocecium thus contains an old 
brown body, and a younger, half-formed brown body; and, as 
is commonly noticed in such cases, new polypide-buds have 
been developed to take the place of the old polypides. One of 
these, already recognisable as a young polypide, was found to 
possess an egg similar to that shown in fig. 15. The colony 
having undergone a complete process of degeneration, it is not 
surprising to find that this egg is developed in a zocecium 
which is younger than either z? or z°. 
It is obvious from the foregoing statements that the first 
appearance of the eggs differs in different cases. Hither one 
or two eggs may be present, and they may occur with or with- 
out a testis. In one case I have found them in all the first 
three zocecia. More commonly I have detected an egg in only 
one zoecium iu acolony. The diameter of the egg is about 
14 (average of four measurements). ‘This is not very differ- 
ent from the measurement (17°6 ) which I have recorded (6) 
