32 FLOWERLESS PLANTS 



called the prothallns. As a rule this process 

 will be about half-an-inch, or something less, 

 in diameter, though it may vary a good deal 

 in the different species of ferns. If we hunt on 

 the moist banks of a hedge round mature fern 

 plants in the autumn, we shall almost certainly 

 find a number of these green scales. An even 

 more easy way to study the development of the 

 prothallns will be to secure a packet of spores 

 from some seedsman (or these may be collected 

 from fronds), scatter them on moist soil, and 

 keep the whole surface closely covered with a 

 tumbler. It is advisable to sterilise the soil in 

 the first instance by baking it in an oven in order 

 to check fungus pests. A close examination 

 of the prothalhis will show that it is secured to 

 the soil by delicate root-hairs, and that it is 

 of a very thin texture, quickly shrivelhng on 

 exposure to a dry air. 



The succeeding stages in the development 

 of the fern plant cannot be followed with the 

 unaided vision. With a powerful hand-lens, 

 or, better still, of course, a microscope, a close 

 examination of the underside of the prothallus 

 will reveal the presence of certain special cells 

 in addition to the root-hairs which have already 



