1888-89.] Mr G. Brook on a New Type of Dimorphism. 83 
In conclusion, attention may be called to the twofold bearing of 
these observations. First, there is the interest attaching to the 
fact of the occurrence of a dimorphism resulting in the formation 
of specialised nutritive and sexual individuals amongst the Anti- 
patharia, such a condition having been hitherto unknown, not only 
in that order, but in the Zoantharia generally. Secondly, the 
specialisation resulting in dimorphism takes a peculiar course, and 
is probably connected with the extension of a colony in the direction 
of its branches. The dimorphism of the Schizopathince , it is to be 
remembered, is brought about by the division of one primitive zooid 
into three, and not as in many other cases by a specialisation of 
different individuals. It thus differs essentially from the dimor- 
phism of Madrepora Durvillei as well as from that of the modified 
individuals which perform similar functions amongst the Hydroids. 
The Change in the Thermoelectric Properties of Wood’s 
Fusible Metal at its Melting Point. By Albert Camp- 
bell, B.A. 
(Read February 18, 1889.) 
The thermoelectric properties of tin, at temperatures below and 
above its melting point, were investigated by the writer about a 
year ago, and the results of the experiments were given in a paper 
read before this Society.* In those experiments, however, the 
height of the melting point of tin made it impossible, with mercury 
thermometers, to obtain anything but an approximate indication of 
the change in the thermoelectric properties in passing the melting 
point. In the present experiments, therefore, Wood’s fusible metal 
was chosen as having a conveniently low melting point. The com- 
position of the alloy used was approximately the following: — 
Bismuth, 
Lead, 
Tin, 
Cadmium, 
50 per cent. 
26 „ 
13 „ 
11 „ 
The metals used were not pure. The melting point was found to 
be 73° C. 
January 16, 1888. 
