1234 General Notes, [December, 
of being detached from the parent. These figures are from 
sketches by Mr. Potts as the process was watched by him at dif- 
ferent stages. It is clear from these figures that the process of 
gemmation in Microhydra is very different from that seen in 
other hydroids; it is, in fact, as if both ends of the young polyp 
were being budded out of the side of the parent simultaneously, 
final separation of the bud occurring at one of its sides instead of 
at its base. The process thus actually makes something of an 
approach toward longitudinal instead of transverse fission. 
he bud after detachment drops down upon an adjacent surface 
and for a time lies quite prone upon its side. It is entirely with- 
out cilia, in this respect resembling the larve of Hydra. It, how- 
ever, seems possessed of slight powers of locomotion, which is 
effected probably by the contractions of the body. After lying in 
its prone position for a time, the vermiform body of the polype 
becomes fixed to the foreign object upon which it rests, by one 
end, while the other end is slowly raised into the erect position, 
when it may be said that the creature is adult. The history of 
the internal changes which the larva undergoes while budding 
are not known, but it is probable that the bud has the oral open- 
ing developed at. its free end by the time it assumes the erect 
position. 
Colonies of two fave been observed by Mr. Potts, appearing 
somewhat as in the sketch in Fig. Æ. This indicates that Micro- 
hydra in common with all other Coelenterata has a tendency to 
form compound individuals or corms. Whether the stomachs of 
such compound individuals open into one another has not been 
ascertained, but it is extremely probable that they do. The pre- 
ceding evidence, taken as a whole, it seems to me, leaves abso- 
lutely no doubt respecting the distinctness of the OR 
n 4 5 
nder the ectoderm of both there is a thin layer consisting 
of contractile processes of the ectodermal cells. The endoderm 
consists in both of large vacuolated cells, containing excentrically 
_ placed nuclei and great numbers of granules at their inner ends. 
These (ae vacuolated, endodermic cells seem to line the whole 
= isa barely discernible thin stratum consisting very probably 
the contractile processes of the outer layer cells. Around and 
withi the lips of the oral aperture the endodermic cells are 
st below the oral eernine and for about one-third the - 
