French NhtionQl Ihsfkute, 3^1 



inif tlie -seed generally served for the noiirishtnent of the 

 younu- plant after germination: but this opinion perhaps 

 had still need of support from posnive observations ; and 

 M. Mirbel, by means of an experiinent equally simple at 

 ingenious, seems to have dispelled }ill doubts on the sub* 

 ject. The embryo contained in the grain of the a|biuin 

 cepa becomes curved on being developed, so as to ionn 

 a tail which issues from the ground, while the radicle and 

 plumule stiU remain under it. If at this period of vegeta- 

 tion we make any mark at an eqdal height on the two 

 l>randies of the geriti, we shall see the speck nearest the 

 tradicle rise alone in the case where the plant receives no 

 Tiutriment except from the juices of the earth : if, on lh« 

 contrary, it be only kept up by liie albumen of the seed, the 

 speck of the plumule will rise above the other ; lastly, the 

 specks will rise nearly equallv, if thje earth and the seed 

 •concur to the development of the germ. It is this last 

 phasnomenon that takes place ; it ceases when the albumen 

 is eii+irely absorbed: in that case the young plant has suffi- 

 cient strength to derive from the earth, or from the atmo- 

 sphere, the nutriments which it will immediately recpiire. 



This memoir is accompanied by interesting observations 

 on the ii^ermination of the asparagus, and on ihe manner in 

 -which tlie leaves of thi-s plan:, sheathing themselves at first 

 like all those of the monocotyledons, become by the growth 

 of the stalk, lateral atid opposite^ and afterwards lateral and 

 alternate. 



In another memoir M. Mirbel has undertaken some nC\v 

 enquiries respecting the germination of the nelumbo. Bo- 

 tanists were not agreed as to the class to which this plant 

 ought to be referred, and as lo the nature of the two fleshy 

 lobes in the nndst of which il takes its origin. Some, not 

 observing^ any radicles developetl in the germination of this 

 plant, thought that it was entirely devoid of them; som« 

 regarded tlie lobes just mentioned as roots ; and others re- 

 -garded them as peculiar organs, and analogous to the viteU 

 ius. It is by means of anatomical observations that M, 

 Mirbel endeavours to di-pel the doubts which these various 

 opinions have raised. He recognised in the first place, iu 

 the nelumbo, all live characters which distinguish the plants 

 with several cotyledons from the plants with a single coty- 

 ledon. He afterwards found in the lobes of this plant ves^ 

 sels analogous to those of the cotyledons, and he observed, 

 ;*t the point where these lobes join, oth'ir vessels which are 

 united in the same manner with those which characterize 

 the radicles la the cmliryos furnisheii witb thi$ organ : 



.Bb4 and 



