736 



LECTURE XL7. 



millimeters high, the stems being furnished with only a dozen or so of leaves. The 

 stem bears at its apex groups of sexual organs, and these groups may almost be 

 spoken of as ' flowers.' The smaller specimens are male, and produce exclusively 

 antheridia, which stand crowded together in large numbers within a rosette of leaves 

 surrounding them like a perianth. The female plantlets are larger and bear at the 

 apex of the stem a dozen archegonia, whicli are surrounded by a more bud-like 

 and closed perigone. 



It has already been pointed out that the archegonia of the Moss and also of 

 the Vascular Cryptogams are fundamentally essentially the same as the oogonia of 



riG. 4iS.—Fii>:nria hygromctrica. A an 

 which has just burst ; a antherozoids (X 350). 

 zoids very strongly magnified ; b still enclosed 

 f a free antherozoid of PolytrichiDii. 



FIG. i,\i.—Fiinaria hygrometrica (a Moss), 

 archegonium before the opening of the cover m 

 of an old archegonium after fertilisation. 



I archegonia ; h enveloping leaves. B a 

 ventral portion with the oosphere. C the 



the Algse, and that in like manner the antheridia are only more complicated in 

 structure than is the case in the latter. 



In Fig. 417 are shown, at A the female flower in longitudinal section, with a 

 group of archegonia at a, and the perigone-leaves in section at b. B represents the 

 anatomical structure of an archegonium at the time when the oosphere is not yet 

 ready for fertilisation, but will be so in a short time. At b is the ventral portion of 

 the archegonium, which is supported on a short and somewhat thick stalk ; from h to 

 m is the neck, which is in most Mosses remarkable for its great length, and which 

 is still closed above, at ;«, by four covering cells. In the ventral portion is seen a 

 long ovoid cavity, from which a canal runs through the entire length of the neck 



