-,8 LECTURE XLI, 



B and C. It will be noticed how the neck h of the arcliegonium, which has now 

 turned red, and is decaying, is still situated above. This still growing venter, 

 investing the embryo as a loose sac, is the Calyptra. 



Enclosed within the calyptra the embryo of the Moss now grows up into a long 

 approximately spindle-shaped body/ the lower end of which bores into the tissue 

 of the Moss-stem, but without coming into true organic connection with it. When 

 this elongated embryo has attained a certain length, the calyptra tears away near its 

 base: the lower part remains attached to the stem as the so-called vaginula, while 



Fig. 419.— ^«««>"i'a hygrometrica. A In- 

 ception of the sporogonium //' in the ventral 

 portion 'b b of the archegonium (optical long, sec* 

 XSoo). B, C, furtherstages of development of the 

 sporogonium y and of the calyptra c; A neck of 

 archegonium X (about 40). 



Fig. /^^sa.-^Funarta hygrometrica. A 

 leafy stem g with calyptra c. fi a plant g 

 with sporogonium nearly ripe : s seta ; f 

 capsule ; c calyptra. C longitudinal median 

 section of the capsule (urn) : ^operculum ; a 

 annulus; p peristome cd columella; h air- 

 space. 5'primarymother-cells.of the spores. 

 The tissue of the columfella becomes loose 

 and filamentous below. 



the whole of the upper part of the calyptra is carried up by the elongating emhryo, 

 which it invests closely, and by which it is nourished. The upper portion of the still 

 stalk-like embryo, within the calyptra, now swells out and becomes thicker : this 

 forms the spore-capsule of the Moss-fruit, the calyptra still remaining on it. 



It would require too much space to describe in detail the development of the 

 Moss-fruit: all that is necessary may be explained by means of Fig. 420. Here is 

 shown (^'m. A) the calyptra still enveloping the whole of the embryo ; at B the latter 

 has already become developed into the Moss-fruit or Sporogonium, consisting of 

 a long thin stalk j (Seta), and the spore-capsule / (Theca) on which the calyptra 



