THE HIGHER CRYPTOGAMIA. 31 



(originally tabular) mother-cell. The turns of the spiral are 

 drawn out from one another, so that it assumes the form of 

 a screw. The spermatozoid moves about with some rapidity 

 in the water, keeping up a continual revolution round its 

 own axis, and often dragging behind it the ruptured vesicle, 

 The hinder end of the spermatozoid is drawn out into a very 

 long, fine point ; the opposite end is thickened, but hardly 

 perceptibly so. At this end I saw very clearly, in sperma- 

 tozoids whose motion had been arrested by a solution of 

 iodide of potash, two long, thin, lateral cilia, exactly like 

 those which Thuret discovered in the spermatozoa of Chara. 

 The observation of these cilia, which I could not succeed in 

 finding in any other liverwort, is a matter of some difficulty 

 even in Pellia with our present magnifying powers. The cilia, 

 and the thread-shaped ends of the spermatozoa, which some- 

 times adhere to other bodies, exhibit an active motion which 

 is winding and helicoid rather than pendulous. One end of 

 a spermatozoid will often remain attached to the mucila- 

 ginous mass which escapes with it from the ripe anthe- 

 ridiuni. The movements of the spermatozoa last only a 

 short time ; ten minutes after their escape they relax sen- 

 sibly ; in all the cases which I have observed, they have 

 ceased entirely after two hours and a half.* 



The number of the antheridia is very large ; it often 

 amounts to fifty on the same shoot. They first open at the 

 beginning of May ; but even at the end of June a good 

 number of ripe ones may still be found. Upon PelliaD 

 growing in running water, which, as a rule, are barren, iso- 

 lated antheridia are not unfrequently found; but arche- 

 gonia are hardly ever met with. 



Upon the shoots situated in the indentations of the fore edge 

 of those spring-shoots which bear antheridia, oval, closely 

 packed cellular bodies are protruded, varying in number from 

 four to twelve; these are the first rudiments of the archegonia. 

 Immediately after their appearance, the young shoot makes a 

 further growth underneath them, but without attaining to 



* Thuret has shown that spermatozoa of a like structure exist in all the 

 AhiscineBe. ('Ann. Sc. Nat./ 3rd ser., vol. xvi). He has given very good 

 figures of those of Pellia (1. c, pi. x). Schacht's figures ('Die Pflanzeuzelle/ 

 Berlin, 1852, pi. v) do not exhibit correctly the relation of the cilia to the 

 body of the spermatozoid. 



