THE VESSELS. 51 



Although there certamly exist facts which prove that 

 vegetable life differs less than has been believed 

 from animal life, and although in particular the recent 

 experiments of Marcet and Macaire tend to give more 

 probability to the existence of a nervous system in 

 plants, I must confess that I am stiU far from affirming 

 that vegetables have a nervous system, or, even ad- 

 mitting^ it, that these corpusciiles perform this function. 

 In fact, they are absent in most of the plants which 

 most resemble animals, such as the Alga9 and Fungi, 

 and they are found in abundance in those where one 

 would least suspect spontaneous motion, as the Lyco- 

 podiaceae. I am disposed to consider these corpus- 

 cules as little glands, destined to co-operate in the 

 nutrition, and perhaps at the same time in the trans- 

 mission, of the juices of one cellule or one tube to 

 the neighbouring cavity. All the physiological argu- 

 ments, by which one would establish the existence of 

 pores or slits, are deduced from the necessity of the 

 transmission of the juices, and shoidd be appKcable to 

 this opinion ; but I only present it as a simple hypothesis 

 which seems to me probable ; and without admitting either 

 visible pores or spongy glands, I do not deny that the 

 membranous tissue cannot be endued with an hygroscopic 

 porosity sufficient to transmit the juices. There is Kttle 

 doubt that different vegetable membranes, which appear 

 homogeneous under the strongest microscopes, are en- 

 dowed with the faculty of differently elaborating the 

 juices ; but, although the diversity of results is evident, 

 we have too much difficulty in isolating the juices 

 furnished by each kind of cellules or vessels,' to affirm 

 any thing of their nature. 



5. What is the affinity of the vessels with the neigh- 

 bouring cellular tissue ? 



This question will be one of the most important to 



