196 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
orderliness which Bergh has described in Mysis, the equatorial planes of 
mitoses lying at right angles to the longitudinal axis of the streak, but 
in Gammarus there are no primitive cells ( Urzellen ). 
Winter and Summer Eggs of Moina.* * * § — Dr. V. Haecker thus con- 
trasts the development of the winter and summer eggs of Moina paradoxa 
Weism. 
Winter Ova. 
Summer Ova. 
Formation of Germinal Layers in Moina.f — Dr. P. Samassa 
answers some recent criticisms of Prof. Grobben, and urges that the 
observations he has made on the development of Moina are supported by 
his own on the Cladocera, and by Hacker’s statement that even in the 
winter eggs of Moina a lower germinal layer is formed by the growth 
of a blastozone. 
Buccal Apparatus of Cirripedia.J — M. A. Gruvel calls attention to 
a hitherto unnoticed arrangement in the mouth of Cirripedes. In 
Balanus tintinnabulurn there is internally to the labrum a chitinous piece 
formed of two symmetrical halves which are fused in the middle line 
and leave a deep groove on the upper part. The upper edge is thickened, 
and on the thickening there are fine but rigid rodlets ; on each side of 
the central cavity on each of the halves there are some very strong 
chitinous setae, much larger than the rodlets. Small pads, each carry- 
ing six to eight rigid setae, are formed on the lower surface in the line 
corresponding to the upper groove. These processes appear to form combs 
which aid in the trituration of food. 
The organs which Nussbaum called enigmatic are shown to be true 
salivary glands, and they have been found in all species that have been 
examined. 
Structure and Functions of Alimentary Canal of Daphnia.§ — 
Messrs. W. B. Hardy and W. McDougall find that, though the mesen- 
teron of Daphnia appears to be a simple tube, it is divided into three 
* Ber. Xaturf. Gesell. Freiburg, vii. (1893) pp. 193-6. 
t Zool. Anzeig., xvi. (1893) pp. 43-1-9. 
X Comptes Rendus, cxvii. (1893) pp. 858-61. 
§ Proc. Cambridge Phil. Soc., viii. (1894) pp. 41-50. 
