212 PHYSIOLOGICAL BOTANY. 



" The peculiarity of the inductive and modern method," 

 says Schleiden (p. 25), "consists in our first completely 

 abstracting ourselves from all hypothesis, not premising 

 any principle, but starting immediately from our direct 

 consciousness, from individual facts, endeavouring purely 

 and completely to isolate these, arranging them according 

 to their essential affinity, ascertaining from them alone 

 laws to which they are subject, and which are essential to 

 their existence, and thus tracing them back, until we 

 arrive at those ultimate ideas and laws, with which all 

 further deduction ceases to be possible." This may be 

 very true ; but it is least applicable when the doctrine of 

 development, anatomy, and physiology are assumed as 

 the foundation of the investigation. The second book, 

 the doctrine of cells in plants, begins as follows (p. 197) : 

 " Cells can only be formed in a liquid which contains 

 sugar, dextrine, and mucilage (cytoblastema). It takes 

 place in two ways : 1st. The mucilaginous parts become 

 condensed into a more or less roundishbody, the cell-nucleus 

 (cytoblast) and at their whole surface convert part of the 

 liquid into gelatine, or comparatively insoluble substance; a 

 closed gelatinous vesicle is formed, the external liquid 

 penetrates into and distends this, so that the mucilaginous 

 body becomes unattached on one side, and remains ad- 

 herent to the other side of the internal walls; it then 

 forms a new layer on its free side, and is thus inclosed in 

 a duplicature of the wall, or it remains free, and is then 

 usually dissolved and disappears. During the gradual 

 distension of the vesicle, the gelatine of the wall usually 

 becomes converted into cellular matter, and the formation 

 of the cell (cellula) is completed. 2d. The entire con- 

 tents of the cell become divided into two or more parts, 

 and from each a delicate* gelatinous membrane is imme- 

 diately formed ; in this manner several cells are simul- 

 taneously developed, which then completely fill the cell in 

 which they were formed." 



Upon how much that is uncertain is this based ! In 

 his explanation, the author himself directly says, " We 

 are far from clear as to the liquid from which the cells 



