76 THE WOOD* 



which it is in contact in all directions. Should 

 you never have an opportunity of examining the 

 plant, you may form a pretty good notion of the 

 manner in which it acts, by twisting a thin slip of 

 India-rubber and burying it under poppy seeds, 

 or some such small bodies. The elastic nature of 

 the India-rubber will enable it to recover its shape, 

 in doing which it will scatter the seeds in all 

 directions. But as there are many species of 

 Jungermannia, and nearly all of them grow in 

 similar situations, that is to say, in moist shady 

 places, you will scarcely fail, if you search in April 

 or May, to find one or other of them. Place one 

 of the seed-vessels under a microscope in the sun, 

 and you will soon see the valves open, and the 

 seeds flying away in all directions. If you have 

 no microscope, I would recommend you to procure 

 what is called a Stanhope lens,* which you will 

 find a never-failing source of amusement and in- 

 struction in your Botanical Rambles. Crush one 

 of the seed-vessels, and, having moistened with the 

 tongue the least convex side of the lens, attach 

 the bruised mass to the glass, and examine it. 

 It will seem at first to be nothing but a confused 

 assemblage of dark-coloured seeds : but watch it 

 closely, and you will discern, that, as the moisture 



* The Stanhope lens is a small cylinder of solid glass, en- 

 closed in a case of silver, or some other metal, and having its 

 two extremities of different degrees of convexity, and conse- 

 quently two foci situated at unequal distances from the surface 

 of the lens. When the most convex side is turned towards 

 the eye, the focus falls exactly on the opposite surface, to 

 which the ohject to be examined should be attached. If 

 turned from the eye, the focus is situated at about the eighth 

 of an inch from the same side, at which distance the object 

 should be held. 



