CHAP. viTi.] MINUTE STRLCTURE. lo; 



character in different plants, it may be worth while to exa- 

 mine more closely than it was at first expedient into their 

 mode of working. In order to understand this, you must first 

 acquire a correct knowledge of the minute composition of 

 the various organs. Now, their minute composition is, 

 generally speaking, so simple that you need find no difficulty 

 in comprehending it ; but the parts of which I have to 

 speak — which build up the leaves, and stem, and root — are 

 so very minute, that unless you make use of a microscope 

 that will magnify, say 40 to 80 diameters, you will be unable 

 satisfactorily to see the parts which compose these organs. 

 In order to meet this difficulty, in case you cannot get a 

 sight of the objects themselves, which is always best, refer 

 to the cuts, which correctly represent all that is necessary. 



2. Take first, if you please, a little morsel of the succu- 

 lent stem of a garden Balsam, or of the stem of any Gourd 

 or of Water Melon. Boil it for a few minutes, until soft 

 enough to be torn or dissected out with needles. If you 

 have none of these plants at hand, a bit as large as a small 

 pea of any soft herbaceous plant will do. Balsam and 

 Gourd are particularly well suited, because the parts which I 

 wish you to examine are not quite so minute in their rapidly 

 developed stems as they are in plants of less succulence 

 and firmer texture. 



We will suppose that you have taken a very small morsel 

 of boiled Balsam or Gourd. You observe that it is quite 

 soft and pulpy, and that a few fibrous strings appear to be 

 mixed up through it. Take a little of the pulp on the end 

 of a needle and put it upon a slip of glass, adding a drop 

 of water. If you have a thin glass cover, put it over the 

 drop, gently letting one side rest first on the slip as you put 

 it down, so as to push out the air-bubbles, which are apt to 

 get entangled, and which look like round balls with black 



