310 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
picture in elegance unequalled by the similar membranes of any of the 
newts.” 
The author is of opinion that ripe mammalian spermatozoa are devoid 
of recognizable structure, and that the numerous and complicated pecu- 
liarities which have been described belong to developing elements. 
B. Histology.* * * § 
Cell-Theory, Past and Present.f — Prof. Sir W. Turner took the 
cell-theory, past and present, as the subject of his inaugural address to 
the Scottish Microscopical Society ; while Protoplasm and the Cell- 
Doctrine was the subject of Mr. C. F. Cox’s J annual address to the New 
York Microscopical Society. 
Influence of Nucleus on Protoplasm.§ — Dr. B. Hofer has made a 
number of experiments on the influence of the nucleus on protoplasm. 
His results may be shortly summarized thus : — 
The cell-nucleus has a direct influence on : (a) the movement of 
protoplasm, in which, indeed, the capacity for movement dwells, though 
it can only be developed in its characteristic forms by its relations to 
the nucleus ; in other words, the nucleus is a regulating centre for move- 
ment ; (fe) digestion in so far as a secretion of digestive juices is only 
possible when nueleus and protoplasm work together. 
The cell-nucleus has no direct influence on the respiration of proto- 
plasm or the function of the contractile vacuole. 
Biology of the CelbU — Sig. E, Verson calls attention to the regular 
changes undergone by the cells of a special mass in the larva of the silk- 
worm. These cells lie below the stigmata, on the fourth to the eleventh 
rings of the body, between the musculature and hypodermis ; they are 
arranged in groups of twenty-five to forty, and may correspond to the 
so-called oenocytes of Wielowiejski. As soon as the process of ecdysis 
begins, the nucleus of these cells loses its rounded form and becomes 
constricted at points ; it diminishes considerably in size, and clear 
vacuoles filled with fluid appear around it in the protoplasm ; these 
vacuoles get nearer and nearer to the periphery, and finally open to the 
exterior. The lumen of the nucleus shrivels up to a narrow cleft. 
Various other changes, best seen in specimens stained with ammoniacal 
carmine, are effected, but at last the nucleus is reconstituted, and the 
whole cycle recommences. 
Phagocytes of Alimentary Canahlf — Dr. A. Buffer finds that the 
wandering cells of the lymphoid tissues of the alimentary canal have 
the power of proceeding to the free surface of such tissues, and of taking 
into their interior lower micro-organisms and foreign matter such as 
charcoal. These wandering cells may be either small and mono- or 
polynucleated cells (microphages), or large mono-nucleated cells (macro- 
phages) ; the latter are developed from the small mono-nucleated 
* This section is limited to papers relating to Cells and Fibres. 
t Edinburgh, 1890, 44 pp. 
X Journal New York Micr. Soc., vi. (1890) pp. 17-44. 
§ Jenaische Zeitschr. f. Naturw., xxiv. (1889) pp. 105-76 (2 pis.). 
11 Zool. Anzeig., xiii. (1890) pp. 91-2. 
^ Quart. Jouin. Micr. Sei., xxx. (1890) pp. 481-505 (1 pi). 
