666 SUMMARY OF CURRENT RESEARCHES RELATING TO 
vulgaris, Gadus minutus , Brosmius brosme , and Arnoglossus megastoma. 
Details only are given, and there are no general results apparent. 
8 . Histolog-y. 
Archoplasm and Attraction Sphere.* — Mr. J. E. S. Moore is of 
opinion that we cannot regard the archoplasmic portion of the attraction- 
sphere as a permanent organ of the cell, any more than ripples are the 
permanent features of the surface of a pond. On the other hand, all 
the normal recent investigations on the karyokinetic propagation of 
cells show that the centrosomes retain their individuality through every 
change. The discoveries of Field with regard to the spermatozoa of 
Echinoderms, and of the author on Mammalian spermatozoa seem to show 
that the centrosomes, unlike the other constituents of the sphere, retain 
their individuality during successive mitoses, and are incorporated as an 
essential constituent of the spermatozoa. 
The observations of Fol, and the more recent studies of Fick, show 
clearly that these bodies assume their old functions as dominants of the 
attractive process in the initial stages of fertilization. We must, with 
Van Beneden, regard them as organs of the cell. 
Chemical Physiology of the Cell.f — Mr. B. H. Chittenden concludes 
his valuable critical review of recent investigations on the physiological 
chemistry of the cell. He discusses especially the nuclein substances. 
Nuclear contents consist of a globulin-like body (as in cytoplasm) 
which may be digested into proteoses and peptones, and of an indi- 
gestible residue of nuclein substances, various combinations of protein 
and nuclein acid, the latter rich in phosphorus. Perhaps these are 
fragments of a still more complex molecule. After discussing the 
xanthin bases, adenin, guanin, xanthin, and hypoxanthin, derived from 
nuclein by treatment with dilute mineral acids, the author says, “ From 
our review we may conclude that the nucleus is in some way intimately 
connected with the processes which lead to the formation of organic 
materials. Whatever other functions it may possess, the nucleus is 
certainly able, in virtue of the properties of its component substances, 
to superintend the metabolic processes which take place in the cell, to 
modify and regulate the metabolism.” 
y. General. 
Function of Equilibration.f — Herr A. Bethe discusses the various 
ways in which equilibration is secured. Touch or a sense of pressure 
is only of importance when the animal moves in air or water and is at 
the same time in contact with some solid body ; in free-swimming or 
flying animals the pressure on all sides is approximately the same. 
There is much evidence in favour of connecting the semicircular canals 
and the otolithic apparatus with this function of equilibration, but what 
of those animals in which these are quite absent ? Delage has sug- 
gested that in insects, for instance, sight is important in this connection. 
But blinded bats fly as securely as before, blind cave-animals and 
* Nature, 1. (1894) pp. 478 and 9 (4 figs.), 
t Biol. Centralbl., xiv. (1894) pp. 375-84. 
x Tom. cit., pp. 95-114 (3 figs.). 
