SHACHT, ON SPERMATOZOID IN THE VEGETABLE KINGDOM. 29 
8. The cilia of the spermatozoids are delicate elongations or 
processes of the protoplasmic layer, although of firmer con- 
sistence than it. They move only during the life of the 
spermatozoid body, and are not retracted after death, appear- 
ing then more like rigid filaments. They may be best seen 
in the dried spermatozoid. 
9. The thickened part of the spermatozoid body and its 
cilia behave towards chemical reagents in the same manner 
as protoplasm. 
10. The granules in the body of the cell-juice of the sper- 
matozoid consist of various substances; some are coloured 
yellow by iodine; others are indubitable starch-grains, and 
in some Algze chlorophyll-granules may be observed. 
11. The form of the filament within the limits of the 
same type may vary to a certain extent, according to the 
genus and species; and this is true especially with respect 
to the length of the body and the number of its spiral turns ; 
and, lastly, as regards the thickness, rounding or flatten- 
ing of the filament, and the number and length of the cilia. 
12. The motion of the spermatozoid proceeds from the 
body itself; it must be regarded as a vital phenomenon of 
the cell, whose protoplasmic contents are very abundant, 
and surrounded also with an extensible and mutable con- 
densed wall of protoplasm. The rotation round fits own 
axis is the principal movement, by means of which the 
spermatozoid screws its way as it were through the water, 
invariably with the narrowest spire, which is furnished with 
cilia in front. A retrograde movement is rarely observed, and 
it is only momentary when the spermatozoid comes in con- 
tact with some solid body. 
13. The duration of the motion in water varies according 
to the species and also according to circumstances ; it may 
be witnessed either for a very short time or for many hours. 
In general the water appears to exert some action on the 
spermatic filaments. ‘The body becomes enlarged, softens, 
and dissolves. 
14, All chemical reagents which act upon albuminous 
compounds are injurious, and even at once destructive to 
the spermatozoids. Amongst the chief of these reagents 
may be enumerated ammonia, nitric acid, iodine, corrosive 
sublimate, alcohol, caustic potass, metallic salts, and tannin. 
They are also killed by a temperature of 50° Reaumur. 
Prussic acid and strychnine are less injurious. Very dilute 
saline solutions produce little effect. 
15. The presence of sugar and other soluble hydro- 
