27 
Some of these remained in their primitive condition 
and developed into hydroid zoophytes; the others 
went further and became primitive worms, and from 
these latter the whole of the Metazoa (including man) 
arose. The structure of Hydra was then fully de- 
scribed, and it was shown how a creature like Hydra 
could, by continuous budding, develop into a typical 
zoophyte, such as Obelia gemiculata. This last was 
explained in detail, and reference was made to the 
manner in which small, free-swimming jelly-fish 
(medusz) arose from the sides of the reproductive 
zooids of the hydroid colony, and how in near relation 
to the radial canals of these medusz the reproductive 
elements developed and afterwards gave rise to the 
adult form. Reference was then made to the structure 
of other zoophytes, such as Bougainvillea ramosa, 
Corymorpha nutans, Tubularia indivisa, Eudendrium 
ramosum, Cordylophora lacustris (a fresh-water species), 
Myriothelhia phrygia, Syncoryne eximia, Hydractinia 
echinata and Clavatella prolifera. 
Friday, 15th May, 1903. Sir Samuel Wilks, 
Bart., F.R.S., in the Chair. 
Mr. Basil W. Martin, F.Z.S., gave a lecture on 
‘“‘Birds; their History and Structure,” illustrated 
with lantern slides, many of which were lent by the 
Society for the protection of Birds, After defining 
the characteristics of birds, and how they differ from 
other animals, the lecturer traced the connection 
between birds and reptiles, and showed how, during 
the course of evolution, birds had been derived from 
reptiles. The skeleton of a bird was next described, 
and the more important features detailed, such as the 
skull with the lower jaw composed of several separate 
bones instead of only one as in mammals ; the breast- 
bone, or sternum, to which the muscles which raise 
and depress the wings are attached, and which in 
