ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
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tho colouring on an old and fading leaf about to fall from the plant ; 
while in a fourth it is a dull, dead brown, like that of a fallen leaf. We 
require to know much more about the history and habits of these forms 
which, perhaps, are not rare, but are only accidentally discovered, in 
consequence of their special coloration. 
Living Fly Larvae in the Stomach and Mouth.* — Herr H. Senator 
relates the case of a patient who spat out about a dozen still living larvae, 
which on examination seemed to be those of the common house-fly. How 
the ova or the larvae had been introduced was inexplicable, and as the 
maggots died, the adult insect could not be exactly determined. 
Coloration of Silk by Foods.! — M. L. Blanc finds that some 
colouring matters, which are very soluble and very diffusible, such as 
fuchsin, can be absorbed by the intestinal epithelium of the silkworm ; 
these substances may then colour the cells of the silk- secreting organs, 
but they do not colour the product of secretion. 
5. Arachnida. 
The Wolf-spider and its Cocoon.J — Dr. W. Henking has watched 
and experimented with Lycosa amentata and Tarentula clavipes, in order 
to discover the exact relations between the female and her cocoon. 
It is well known that mother-spiders guard the cocoon with great care, 
yet experiments show that this does not depend upon the presence of 
young in the cocoon, but on its “ odour ” (?) and definite weight. That 
odour is one of the credentials is an inference, in regard to which Dr. 
Henking repeatedly says that he is only prepared to maintain that the 
spider has some discriminating sensitiveness nearer to smell than to any 
other human sense. A false cocoon with any sort of contents or with 
any kind of surface will be carried about by the deluded parent provided 
that the aforesaid odour be detected. A portion of the genuine envelope 
is sufficient to render a foreign body acceptable. On the other hand, 
after carrying an artificial cocoon for a while the spider will throw it 
away, and this Henking regards as deliberate. Nor has he any doubt as 
to their memory, for spiders seek patiently for a lost cocoon, and re- 
commence the search even after prolonged interruption. Moreover, they 
seem to have an instinctive feeling when the hatching of the young is 
about to occur, and will dip the cocoon in water, as if to hurry the young 
out. The visual power is regarded as slight, but the tactile and auditory 
senses are acute. The formation of the cocoon and many more general 
facts in the life of these spiders are graphically described. 
Gall-mites.§ — Dr. A. Nalepa continues his systematic study of gall- 
mites or Phytoptidae, describing and figuring 12 new species of Phytoptus , 
and 4 of Phyllocoptes. In a list of all the forms which he has described, 
we find 29 species of Phytoptus , 7 of Cecidophyes , 11 of Phyllocoptes , 1 of 
Acanthonotus , and a note of the plants on which they live and of the 
malformations which they cause. It is generally true that different 
forms of Cecidia are at once referable to different mites, but Nalepa 
* Berlin. Klin. Wochenschr., 1890, No. 7. Cf. Centralbl. f. Bakteriol. u. Para- 
sitenk., viii. (1890) pp. 150-2. t Comptes Rendus, cxi. (1890) pp. 280-2. 
X Zool. Jahrb., v. (1890) pp. 185-210. 
§ SB. K. Akad. Wiss. Wien, xcix. (1890) pp. 40-69 (7 pis.). 
1890. 3 E 
