550 TRANSACTIONS OF SECTION D. 
found in sections of a young lanice which had just commenced to build its sandy 
tube, and it is, moreover, not to be found in the adult werm. 
2. Demonstration of Skin Varieties of Cricetus frumentarius of Thuringia. 
By Professor H. Simroru. 
The hamster is a rodent a little larger than the guinea-pig, living in cornfields, 
where it digs holes under the ground, It carries in its cheek-pouches a quantity 
of corn, which it accumulates in a compartment of its hole as provision for the 
winter time. It propagates rapidly, and, being of a very quarrelsome nature, every 
individual lives by itself in its own hole. The damage caused is enormous, the amount 
of corn in a single hole sometimes reaching as much asa bushel. For this reason 
the animal is dug out and killed in the autumn by special hamster hunters, who 
profit by the corn and by the skin. To show the quantity of hamsters in one 
district, I may say that in a field in the district of Halberstadt more than ten 
thousand were killed in one year. 
The headquarters are in the North of Germany, between the mountains of 
Thuringia and the Hartz, this being the northern limit. It spreads to Western 
Germany, where smaller numbers inhabit the neighbourhood of the Rhine River, 
The hamster inhabited the same countries before the Diluvium period; it 
disappeared during the Glacial epoch, but subsequently immigrated from Russia. 
The pretty skin is used for the lining of fur coats, as many as two hundred specimens 
being used for a coat of large size. The colour of the animal is grey or reddish- 
grey, the under-side black. Both parts are separated by a more reddish part 
surrounding the body. At the side of the head and the breast it is interrupted 
by three white patches, so that the forepart of the body is vividly coloured. 
Some years ago, during the hot summers, I heard that black specimens were 
seen in the warmest parts of Thuringia, some of which I received both alive and 
dead. These were demonstrated in the ‘ Naturf. Ges.’ of Leipzig with the hope of 
getting more information. The skinners’ attention was drawn to the subject ; it 
was then possible to obtain more specimens. 
The amount of the annual harvest of hamsters in Germany is about a million, 
three quarters being obtained in Thuringia and one quarter in Western Germany. 
From among the greater stock of 750,000 specimens were taken the different varia- 
tions which [ now put before you. I have discarded all irregularly variegated forms, 
You will see a surprising amount of variability. First, there are the normal 
forms ; here one fact is of interest—namely, that in the young animal the black 
pigment was found in the cutis, later on only in the hair. The next change of 
colour is the disappearance of the red, and later that of the white patches. The 
upper side becomes grey or greyish brown, finally blackish, so that the whole 
animal becomes uniformly black. In another direction the ventral side becomes 
lighter, the upper side varying in the way previously mentioned. In one speci- 
men it is reddish, with white patches; in others, greyish or ochreaceous. As 
a further variation the under-side becomes white, and finally there is a perfect 
white or albino form, and L have been told that this form is the rarest. However, 
I suppose that this is not the continuation of the former series, but a phenomenon 
by itself. Here we have a maximum of variations in a mammal. What is the 
significance of all this? Have we to do with atavistic forms, or with prospective 
ones? Or can we observe here the mere influence of climate? One of the forms 
appears to be identical with the Syrian Cricetus auratus. 
3. Plankton Fishing off the Isle of Man. 
By Professor W. A. Herpman, /.2.S. 
During recent years a good deal of attention has been paid by naturalists in 
various parts of the world to the quantitative distribution of organisms in the sea. 
It is obvious that exact information in regard to such a matter may be of enormous 
