THE HIGHER CRYPTOGAMIA. 79 



fruit. This production takes place after the multiplication 

 of the apical cells of the young fruit in a longitudinal 

 direction has terminated (PL XII, fig. 8). The two 

 covering layers of cells form the capsule-wall, having first 

 multiplied considerably by often repeated longitudinal and 

 transverse divisions which take place by septa perpendicular 

 to the outer surface. The capsule-wall, in consequence of 

 the rapid increase of the number of its cells, eventually 

 becomes hemispherical (PI. XII, fig. 9). Most of the 

 somew r hat elongated cells of the horizontal cellular surface, 

 enclosed by the capsule-wall, follow the progress of the 

 latter as its arched surface becomes elevated, dividing 

 repeatedly by transverse septa; some, however, expand 

 only in a longitudinal direction until they eventually assume 

 the form of narrow cylindrical tubes, parallel to the longi- 

 tudinal axis of the fruit. These tubes are attached at the 

 base to the upper end of the fruit-stalk, and at their apices 

 touch the inner arch of the capsule-wall (PL XII, fig. 9). 

 The latter are the elaters ; the tessellated cells produced 

 by the division of the elongated cells, become the spore- 

 mother-cells. 



Contemporaneously with the earliest period of the de- 

 velopment of the rudimentary fruit of liverworts, there 

 commences a very active multiplication of the peripheral 

 cells of the ventral portion of the archegonium, which thus 

 becomes the calyptra, The cell-division, which occurs 

 repeatedly and in rapid succession, often extends far down- 

 wards into the tissue of the branch which bears the im- 

 pregnated archegonium. Whilst the lower part of the 

 archegonium becomes transformed into the upper half of 

 the calyptra, its distended form becomes compannulate 

 {J. bicuspidata, PL VIII, fig. 6 ; Radula complanata, 

 PL XI, fig. 4). The lower portion of the calyptra is 

 formed out of the upward- growing tissue of the tip of the 

 shoot upon the apex of which the archegonia stand. The 

 abortive archegonia often appear pushed up high on the 

 side-walls of the calyptra, which has originated from the 

 impregnated archegonia (PL XI, fig. 4, Radula com- 

 planata) . 



No distinction can be traced between the base of the 



