^35 



square by three inches deep, were therefore prepared and 

 steriHzed by hot water as before, and small clumps of 

 prothalli, about one-third of an inch across, were pricked 

 out with a penknife and inserted an inch apart, being just 

 pressed home by the finger in little cavities made to 

 accommodate them. A sheet of glass was then laid over 

 each pan, and these were placed on a well-lighted shelf. 

 The result was, that in a few weeks the pans were as full 

 of young plants as the original ones were of prothalli, 

 necessitating the supply of further room. To afford this 

 it was now^ necessary to separate not merely clumps of 

 prothalli, but young rooted plants, and it is here perhaps 

 that a hint is welcome as to how to do this with a 

 minimum of loss where the crop is of such a character, 

 that the loss of even a minute plant may mean the loss 

 of a great prize. My plan is this. Each clump of 

 youngsters resulting from a patch of prothalli is easily 

 extracted intact. Taking a deep soup plate filled with 

 water, the clump is immersed in this up to the young 

 growth, and the soil is thus so softened and the roots so 

 loosened, that beginning at the outside every individual 

 plant can be coaxed away with its fronds and roots, and 

 even the still adherent prothallus absolutely undamaged, 

 not one being thus sacrificed. Other pans are now pre- 

 pared, not necessarily sterilized this time, but of fine open 

 soil, and, again, an inch apart the now individualized 

 youngsters are inserted, and will now in a greenhouse 

 reach a size large enough to enable them to display their 

 character, when of course selection can be made, the 

 best and most promising being extracted, again an easy 

 task, since if the soil be thoroughly wetted, they can be 

 extracted by a gentle pull, leaving the rest undisturbed. 

 By acting as above, it is an actual fact that no check 

 whatever is suffered in growth, quite the contrary indeed, 

 for in the case under consideration Polystichums sown last 

 July have now, in October of this year, fronds three to four 

 inches long with vigorous growth in progress. It may 



