On the Chemical and Natural History of Lwpuline. 205 



still more numerous than in the preceding figure. It 

 not unfre(iuently happens that the utricular multiplica- 

 tion parallel to the rays is more marked than that which 

 occurs in the other direction, in which case the section ap- 

 pears as in figure 15. It is at this stage of development of 

 the lupuline that its edges hecome raised ; then from the 

 discoid state it becomes cup-shaped. Figure 16 represents 

 some of these cupules which are almost arrived at the per- 

 fect state. They have longitudinal striae, interiorly and 

 exteriorly ; that is to say, in the direction of the utricular 

 multiplication parallel to the rays. These elegant cupules 

 appear sessile in consequence of the pedicel not being elon- 

 gated. 



When the enlargement of the cups has ceased, other 

 phenomena take place in the interior of their tissues. Each 

 cupule consists, at this time, of a layer of cells, which is 

 covered with a cuticle on its two faces, the interior and 

 exterior ; then commences the secretion of the yellow liquid 

 before mentioned. It is poured out on the whole internal 

 surface of the cupule between the secreting cells and the 

 cuticle which covers them. The latter, detached from the 

 cells by this flowing, is gradually raised completely from 

 the whole extent of the internal surface (fig. 17 c?), and 

 finally pushed up like the finger of a glove ; it is now that 

 the lupuline takes the form of an acorn (figs. 18 and 19), 

 to which I have compared it ; it is then arrived at its most 

 perfect stage of development. 



It is curious to observe under the microscope the rising 

 of the cuticle. It may be caused artificially, by placing 

 the cupules in water slightly alkalised, which penetrates 

 their walls better than pure water. They may be seen suc- 

 cessively passing through all the intermediate stages be- 

 tween the form I of figure 16 and that of figure 18. 



If we examine the fresh but perfectly developed lupu- 

 line in water, it is seen to swell gradually, becoming turgid 

 by endosmose, then all the cells of the cupule appear as a 

 perfect network, and it is then evident that the imprints 

 marked upon the cuticle disappear almost completely. The 

 enlargement increases to the point of bursting of the grain, 

 and it then emits a perfect cloud, formed by a multitude of 



NEW SERIES. VOL. XIX NO. II.— APRIL 1864. 2 D 



