]^gO KANSAS ACADEMY OF SCIENCE. 



organs by vibrating rapidly. Thus they move about swiftly, as soon as freed 

 from the antheridium; though they must always have water in which to float 

 into the open archegonia, and for this reason the antheridia never bursts when 

 dry ; the antheridia and spermatozoids are best studied in Polytrichum, where 

 they are comparatively large. (See plate XXII.) 



The origin of the antheridium is not uniform, but differs in different species. 

 In Sphaguni it originates in the place of a new shoot, while in Fontinalis and 

 most other mosses the origin varies: even being different in the same flower: (see 

 " Goeble's Special Morphology," p. 175, and " Sach's Text-Book of Botany," 

 p. 372.) 



The female flower is inclosed in leaves called the perichaetium or perigynum. 

 These leaves also are often much modified, becoming hyaline, delicately mem- 

 branous, or much elongated into a hairlike point, in some species, while the base 

 becomes sheathing or involute. The perichaetial leaves are usually larger, 

 longer, and more pointed than the perigonial leaves. 



The archegonia or female organs, which are analogous to the pistil of a flower, 

 are flask-shaped bodies on a short, thick stalk or seta. The thick part or ventral 

 portion resting on the seta is termed the venter or germen, and incloses the 

 germinal cell or oospore. The upper slender neck is usually twisted on its axis, 

 and is called the neck or stylidium. The venter wall, before fertilization, is two 

 cells in thickness, and extends up into the neck, which is only one cell thick. 

 This neck or stylidium consists of four or six rows of cells inclosing a central row 

 of cells, termed the canal cells. These canal cells become mucilaginous when the 

 archegonium is matvu-e and receptive; and swell, forcing apart the upper cells^ 

 making an open canal down to the odspore, through which the spermatozoids 

 entea- for fertilization. The spermatozoids, as soon as they escape from the an- 

 theridium into the water surrounding them, move very rapidly until finding an 

 Open archegonium, which they enter, jjassing down the canal to the oospore. 

 Schimper and others have seen the spermatozoids in the canal. Usually but one 

 archegonium in a flower is fertilized or develops; but in a few mosses several are 

 matured fi-om the same flower, as in Climacivuu dendroides, and others. (See 

 plates.) 



The origin of the archegonium varies as much as the antheridium; and in 

 Sphagnum it originates at the apex of the female shoot; and also in the typical 

 mosses (see Goeble's Special Morphology, p. 176, and Sach's Botany, p. 375). As 

 the fertilized archegonium grows, the inner leaves of the perichaetium grow 

 larger, forming a sheath around the base of the seta, as in Dicranum, Mnium, 

 and others. 



The fertilized oospore now begins to grow down into the tissue of the apex 

 of the stem, firmly imbedding itself; while it also grows upward, forming a seta 

 or stalk, which bears the capsule or theca inclosing the spores. 



The oospore, in growing upward, tears away the upper part of the archegonium, 

 carrying it upward, where it usually remains attached, forming the calyptra or 

 veil; while the lower part forms a sheath inclosing the base of the seta, called 

 the vaginule. 



The sporogonium (sporophore or sporophyte), which the developed oospore is 

 called, almost reaches a perfect development in the venter of the archegonium of 

 Sphagnum. 



In Sphagnum, x\ndreaea, and Archidivim, the seta is very short, but in most 

 mosses it becomes quite long. 



The calyptra entirely covers the young capsule, and is usually membranous, 

 thin and smooth; but sometimes it is densely hairy, or hispid, as in Polytrichum 



