522 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
food by means of intracellular digestion, which is effected by the cells 
of the mantle of the embryo. Later on the mantle undergoes a meta- 
morphosis which is a true process of regeneration, for the cells which 
have fulfilled their function are replaced by other new and, at first, 
resting cells. This replacement of cells is accompanied by a sharp 
change in function, for while the cells of the mantle of the embryo have 
a function which is unusual for ectodermal cells, namely, that of nourish- 
ing the organism and of intracellular digestion, the cells which take 
their place return to the normal function of the ectoderm, for they form 
ordinary tegumentary cells. This and other results of the author are, 
as he points out, of wide interest. A little reflection shows that the 
embryonic ectodermal cells of Mammals have the same power of taking 
up nutriment. The cells of the chorionic villi and the chorionic epi- 
thelium have this same phagocytic peculiarity. This striking functional 
resemblance between the chorionic epithelium of the mammalian embryo 
and the embryonic mantle of the parasitic larva of the mussel may afford 
a new support to the hypothesis that the embryo in viviparous animals 
is in the relation of a parasite to the body of its mother. Another phe- 
nomenon in the nourishment of the Glochidium, the peculiar pathological 
changes which are seen in the corium of the fin, may be compared with 
the formation of that nutritious substance (placenta), which in Moina 
serves for the nourishment of the embryos which are developed in the 
brood-space of the mother. Similarly the fact that in the destruction of 
the parasitic organism the phagocytes of the host come into action, 
appears to find a parallel in the developmental history of the Mammalia. 
If a foetus dies in the uterus of its mother, there appear in the tissues of 
the former a number of small cells which are like lymph cells. These 
wandering cells are, the author thinks, nothing more than phagocytes, 
which wander into the embryo from the organism of the mother. 
Bryozoa. 
Bryozoa of Africa.* — Dr. M. Meissner gives us the first account of 
the Bryozoa of East Africa. Four species only, and those already 
known, appear as yet to have been discovered. 
Arthropoda, 
a. Insecta. 
Senses of Insects.! — Prof. C. V. Riley has an exceedingly interest- 
ing article on this subject to which we can do little more than refer. 
The suggestion appears to be new that the highly developed and delicate 
antennae of the male Ghironomus may be likened to an external brain ; 
its ramifying fibres corresponding to the highly complicated processes 
that ramify from the nerve cells in the internal brains of higher animals, 
and corresponding in a somewhat similar way to external impressions. 
The author states that he has no sympathy with that class of materialists 
who refuse to recognise that there may be and are subtle psychical 
* ‘ Deutsch-Ost-Africa. IY. Die Thierwelt. Die Wirbellose Thiere,’ Berlin, 
1895. See Zool. Centralbl., ii. (1895) pp. 243-6. 
t Nature, lii. (1895) pp. 209-12 (5 figs.). 
