16 
ating caudal appendage raised. Of course there are very rare 
instanees where it was right to take only a head, for instance, 
when the body was badly shaped, deformed, or injured ; but 
these were very exceptional circumstances, and he would, there- 
fore, urge the professional photographer the wide world over to 
look to this matter at once, and try to introduce a little more 
life and expression into his animal photographs, particularly into 
those of the horse, dog, or cat. The Lecturer closed with the 
exhibition of a fine series shewing how to do it. 
WEDNESDAY, MARCH 11TH. 
OBSERVATIONS AND EXPERIMENTS ON 
THE MARKINGS AND COLOURING OF 
LEPIDOPTERA AS AFFECTED BY TEM-— 
PERATURE, 
BY 
MR. EF. AEE RRIFIELCD: 
In some experiments with English moths, lately instituted on 
the suggestion of Mr. Francis Galton, connected with that gentle- 
man’s researches in heredity, the author had been led to follow 
up certain collateral lines of investigation as to the relations 
between climatic conditions and the markings and colouring 
of Lepidoptera, a subject of some interest in its bearing on 
recent geological history. Mr. W. H. Edwards, in America, 
and Prof. Weismann and others, in Germany, had shown that, 
by subjecting the pupz of certain butterflies, known for their 
“seasonal dimorphism,” to a low temperature, the Summer 
form could be converted, or nearly converted, into the very 
different Winter form, but that the endeavour to obtain the 
converse result always failed. Weismann’s theory was that the 
Winter form was the ancestral one, and that as the glacial period 
gave place to a warmer and longer Summer, the second or 
Summer brood was interpolated, and had a tendency, when 
subjected to a low temperature, to revert to the old form. Mr. 
Merrifield’s experiments on some English seasonally dimorphic 
