1902] CURRENT LITERATURE 167 
asthe 16-celled stage, by placing them in an extract of the sperms of the same 
species. The sperms were extracted both in distilled water and in concen- 
trated sea-water, at a temperature of 70°, which is fatal to them. The 
earact was brought nearly to the concentration of normal sea-water (by the 
addition of concentrated sea-water or of distilled water, as the case 
demanded), and the unfertilized eggs were placed therein. The extract as 
used had a somewhat higher osmotic pressure than that of normal sea-water, 
but the author shows that this is not a fatal objection to his experiments, since 
the same concentration of KNO;, MgCls, etc., produced no response in the 
| BES. Neither did a similar extract made from the sperms of another species 
stdin effect. What is the nature of the chemically active body here 
‘“smonstrated, the author cannot yet say. He closes the paper with some 
femarks upon the theory of fertilization.— B. E. LIVINGSTON. — 
i... has recently made another contribution to the knowledge of 
as bes ae and morphological researches upon the sperm cells 
eae Plants indicate that the cilia and spiral bands of plant sperms 
O° hee seaaiaed to the tail and head of animal spermatozoa. The 
hee iets oe ie are distinguished chemically by their nuclein con- ae 
ee < “eg cking in the cilia and in the tail. Besides many animal es 
BO, Polytech ea eae the sperms of Nitella, Chara, Ceratopteris, a 
; ; 3s a 7. other plants. The various forms were treated wi ; oe 
_ ae a (sodium sulfate to gr., acetic acid 1 gr., water 
ae nis solution a little acid fuchsin was added. This sharply 
vetes the nuclein-containi 
© not stain. The tail and middle piece, however, 
20a of Triton ; nis used. When alcoholic material of the sper- : 
idle ae ae 's treated with the fuchsin-containing solution, the tailand 
itensely, The b se at all swollen but become stained, the latter very 
may be due to a deli 4ppears swollen and slightly stained, but the staining - 
BD 
Of the head. oo. covering and not to the nuclein-containing content | 
ror pad ase of Chara and Nitella show the anterior and pos 
t Portion is not at ae all swollen but intensely stained, while hy 
af ae tye ‘Stained but is very much swollen. Za arias as 
b blephur, ey the middle piece of Triton and the salmon, as 
iddle piece. e Cb2t2 and Nitella, contain no nuclein. Tix 
eu co. .  arously used, but only when it is of centrosome 
—@ 
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