290 ON THE PROGRESSIVE DEVELOPMENT OF 



become elongated or depressed, according to the circumstances 

 of pressure under which the expansion takes place — the outer 

 filmy covering or envelope may increase in thickness, and the 

 secondary vesicles of which this film consists become so far 

 developed as to be sensible to our modes of investigation — and 

 lastly, the organic molecule may acquire the property of repro- 

 duction, and by the formation of other vesicles from the inner 

 surface of its filmy covering, or more probably by the develop- 

 ment of the pre-existing particles of which this covering is 

 composed, the vesicle which was either simple, or to our senses 

 apparently so, becomes compound, having its central portion 

 occupied with other and secondary vesicles. That these are not 

 merely speculations has been fully established by the researches 

 of M. Raspail upon the minute chemistry of organic products. 

 In examining the granules or vesicles of fecula, a vegetable 

 product of great importance, and of which the seeds and roots 

 of many plants almost entirely consist, he observed that, sub- 

 jected to a limited artificial heat, the membrane or filmy 

 envelope constituting their external coating was capable of 

 gradual extension, the granules increasing in size, and that at 

 the same time globules were formed all over its surface, resembling 

 new grains of fecula, attached by a hilum or minute scar to a 

 membrane. " Analogy," observes M. Raspail, " seems to point 

 out before hand that, under the influence of the natural causes 

 which afiect vegetation, whose action though slow is durable, 

 this development should possess a more regular character 

 than under the influence of an artificial cause. What is thus 

 indicated by anidogy is proved by observation, in regard to the 

 grains of fecula, which grow in the vegetable organs, till their 

 forms and dimensions might render it difficult to recognize them. 

 On the other hand, direct observation shows that, in consequence 

 of this development, there are formed in the interior of each 

 grain of fecula, new feculent globules, which being packed 

 together, present a very perfect resemblance to the cellular 

 texture. Each of these grains of fecula, when obtained separate, 

 is furnished with a hilum, by which it was connected with the 

 inside of the cell which contained it, just as a bean is connected 

 by its hilum with the placental parietes of the large cell which 

 we call the pod. But this bean is not merely stuck on to the 

 surface of the pod ; it has been developed by the progressive 

 swelling of the inside, and has passed successively through every 

 dimension from that of a microscopic globule to that which it 

 possesses when ripe." — "The secondary grains, whose presence 

 we have detected in its interior (i. e. of the primary vesicle), 

 acted on by the same causes, will be developed in their turn, and 

 will in turn give rise to other tertiary grains, and so on inde- 

 finitely ; so that we shall then have a more or less complicated 

 cellular texture in the interior of a single cell. Now as these 

 new cells are, at every period of their growth, attached to the 



