58 SPERMATOGENESIS AND FECUNDATION OF ZAMIA. 
other. A tremulous vibration of the cilia, apparently independent of 
the rhythmic contraction, can be observed in the weaker motion of 
extreme youth and age. Whether this occurs in the period of vigor- 
ous rapid motion could not be determined, but there would seem to be 
no reason why it should. It would seem to be a nervous action con- 
nected with weakness. The motion of the spermatozoid as a whole is 
comparatively slow and sluggish. 
The movement of the living spermatozoids of Ginkgo was observed 
by Hirase, but only in a fewinstances and was not carefully described. 
Those of Cycas have as yet not been observed in a living condition. 
In September, 1898, Fujii (89) made a somewhat detailed study of 
the living spermatozoids of Ginkgo, and as his paper is published in 
Japanese and is thus inaccessible to many, an outline of his observa- 
tions will not be out of place here.t As in the case of the writer’s 
study of Zama spermatozoids published in 1897, Fujii used a 10 per 
cent solution of cane sugar in studying the Ginkgo spermatozoids, and 
succeeded in keeping them living for several hours. 
At 11.37 a. m. a spermatozoid escaped from a pollen tube and moved slowly, but 
with definite rate, for thirty minutes; afterwards it stopped and only moved its body 
atadefinite place. At1.050’clock p. m. only a ciliary movement was observed; at 1.30 
p- m. it stopped all motion, as if dead, but soon afterwards it regained its ciliary move- 
ment, and finally at 2.05 p. m. it ceased all motion. — 
The second spermatozoid studied appeared from the pollen tube at 4.20 p. m. and 
moved in and out of the field of the microscope for one hour and twenty-five minutes. 
Afterwards, by a careless mistake, the sugar solution dried up and it stopped all 
motion. Besides these two spermatozoids I observed four others, but they lived . 
only a short time. One spermatozoid observed by Mr. Yobe lived for three hours. 
Fujii described the motion of the spermatozoids in swimming as 
similar to that of. infusoria. 
It is a very interesting fact, as observed by Fujii, that the sperma- 
tozoids occasionally cease all motion, as if dead, and after remaining 
in this quiescent condition for a time begin motion again. I have 
observed this many times in Zama. Frequently the sperms swim 
very actively for a time and then cease motion, as if desiring rest, and 
later begin motion again. It would hardly seem probable that the 
sperm could absorb nourishment from the surrounding media and gain 
energy in this way for furtber motion, but this may be the case. 
Later, in 1899, in a second paper, Fujii (40) described further obser- 
vations on living spermatozoids and the methods by which they get out 
of the pollen tubes in sugar solutions. An extract from his description 
follows: | 
The spermatozoid in the mother cell moves its body gently and turns over in many 
directions by the ciliary movement, assuming various shapes, slightly changed by the 
simultaneous pressure of the mother cell and the two spermatozoids. At the same 
time, and owing to the same pressure, the nuclei also changed their form. The 
1 Fujii’s papers were kindly translated for the writer by Dr. H. Ikeda. 
