12 HOFMEISTEll, ON 



of the entire mass of cells is not thereby materially affected. 

 The enlargement which takes place in a direction radial 

 to the axis of the fruit, and the cell-multiplication in the 

 direction of the sides of the paraboloid which constitutes 

 the apex of the rudimentary fruit, are somewhat more 

 extensive in the cells derived from the wider cells of the 

 second degree than in those derived from the narrower 

 ones. The outline, as seen from above, of the mass of 

 cells produced by the multiplication of each rectangular 

 combination of four cells of the second degree, which out- 

 line is at first elliptical, becomes consequently soon trans- 

 formed into a circle. 



The innermost of the cells into which each cell of the 

 second degree divides is separated by longitudinal septa 

 into two halves. Immediately under the apex, the fruit- 

 rudiment consists of four axial longitudinal rows of cells, 

 which are covered by an almost entirely simple layer of 

 peripheral cells (PL I, fig. 24). The fruit-rudiment in- 

 creases in thickness and circumference by the growth of 

 tangential longitudinal septa in the peripheral cells, which 

 growth is always repeated in the outermost of the new cells, 

 and alternates with the formation in the same cells of radial 

 longitudinal septa. The cells of the base of the very young 

 fruit-rudiment expand considerably in breadth, and thus 

 lay the foundation of the flattened spheroidal enlargement 

 by means of which the fruit is buried in the cellular tissue 

 of the stem (PL I, figs. 21 c > 22). At the period of the 

 middle age of the fruit, the cells of this swelling not only 

 attach themselves very firmly to the neighbouring cells of 

 the stem, but force themselves inwards between the latter 

 cells to some depth, becoming transformed into cylindrical, 

 crooked papillae, comporting themselves like short radicular 

 hairs (PL II, fig. 5). 



The cells of the stem which adjoin the archegonium 

 multiply actively in all three directions of space during the 

 development of the fruit-rudiment. By this means the 

 surrounding tissue keeps pace, for a considerable time, with 

 the increase in size of the fruit-rudiment (PL I, fig. 19 ; PL 

 II, fig. 1) ; afterwards it usually so far outgrows the latter, 

 that a wide hollow space, filled with tough gelatinous 



