INVERTEBKATA, CBYPTOGAMIA, MICROSCOPY, ETC, 123 



rudiment of the tlieca, tlie foot of tlie sporogonium, the remainder 

 (6-8) the sterile apex of the capsule. 



3. The spore-layer belongs to the basal square (endothecium of 

 Kienitz-Gerloff), and is separated from it by the first tangential division. 



4. The outer and inner spore-sac are formed by secondary division 

 in the wall of the capsule or columella. 



II. As to Sphagnum : — 



1. The fertilized oosjihcre divides into two halves by a septum ; 

 in the lower basal half only a few more irregular divisions follow ; the 

 sporogonium originates from the upjier half. 



2. The apical growth is efiected by transverse walls ; the number 

 of transverse disks thus formed is only from six to eight ; the entire 

 remaining longitudinal growth takes place by intercalary division 

 within the basal part. 



3. Each basal part, including that of the apical cell, breaks up, in 

 succession from the oldest to the youngest, by cross division into fuur 

 squares ; the divisions of any two basal parts that lie immediately one 

 above another cut one another at an angle of 45°. 



4. In each square the division follows into inner and outer colls (the 

 basal square and peripheral layer of the wall of Kuhn), either by two 

 successive divisions, or by only one, as in Ephemerum and most mosses. 



5. The inner cells or basal square are the origin of the columella ; 

 the outer cells, or j^eripheral layer of the wall, form the spore-layer 

 and the wall of the capsule. ■ 



6. The separation of the spore-layer from the layer of the wall is 

 effected by the first tangential division. 



7. The outer and inner spore-sac are formed by secondary division 

 from the wall of the ciipsule or the columella. 



8. Only the three uppermost basal parts, including that of the 

 apical cell, take part in the formation of the spores, while the 

 remainder, with the basal 2)art of the rudiment of the thcca, form 

 the bulbous foot and the neck of the sporogonium. 



9. In the ripe capsules of all the species examined (Sphngmim acii- 

 tifolium, cnsjndatum, cuspidatum var. plumosum, and ricjidum) only one 

 kind of spore was invariably found. 



10. In both Andrecea and Sphagnum, the fertilized oosjibcre, as 

 well as tlic moderately developed eni])ryo, are always surrounded 

 by a hyaline coagulated mass of mucilage, wliich exhibits protein- 

 reactions, and is drawn out into an appendage, which reaches so far into 

 the neck of tlio archcgonium as the latter lias not assumed a browncolour; 

 one or mcn-o anther(jzoids are always found embedded in this mucilage. 



Stomata of Marchantiaceae.* — The comparative anatomy of tlio 

 Marchantiaceai, especially in relation to their stomata, has been made 

 a subject of study for several years by W. E. Alwin Voigt, who first 

 lays down the terminology of the subject as follows : — 



The term pm-r. ho applies exclusively to the actual opening to the 



stoma through the epidermis (or the entire opening wliere there is a 



border). The diflerentiatod epidermal colls which enclose the pore are 



the guard cells. The structure eipuvalcnt to them which results from 



* 'Bdt. Zcit.; xxxvii. (isTlt) pp. 7211, 715. 



