40 FERN GROWING 



antherozoids from a number of different antheridia have 

 helped in these fertihsations. In sowing varieties of the 

 Lady Fern, I have raised the combination of five and six. 

 This is alluded to in my paper ' On Prothalli.' These plants 

 that gave evidence of multiple parentage were obtained in the 

 identical manner formulated before they had any existence. 

 Spores require to be sown thickly to enable the prothalli to 

 intermingle, otherwise they are only fertilised from the same 

 prothallus. 



"If we take the reasoning of Sir John Herschel on the 

 doctrine of probability and apply it to these trials, the chances 

 against the view adopted being incorrect are as great as that 

 of the haphazard distribution of the stars. 



" These experiments regarding the changes in animal and 

 vegetable life were commenced forty years ago. Bearing to 

 some extent on this subject, experimenting on the mimulus, 

 a yellow variety was crossed with a spotted one, and the 

 seedlings were spotted ; later on, and further up the same 

 stem, two blooms were then crossed with a yellow one, but 

 the seedlings were still spotted. The effect of the first cross 

 had become a part of the life-history of the plant ; in a second 

 experiment the same plant was simultaneously crossed with 

 pollen from two other varieties, and several of the seedlings 

 are combinations of the three. It requires dexterity in crossing 

 the mimulus, as the lips of the pistil are as sensitive as the 

 leaves of the sensitive mimosa. Natural changes are slow, 

 but culturally we can accelerate that process which continues 

 age after age. The germ once changed, the new element is 

 retained, it becomes combined with others until the normal 

 appearance is lost. The illustration of the Hart's - tongue 

 shows this alteration, helped on as it were by artificial means 

 that have accelerated the process, and these changes will 

 continue whilst the world lasts'. Darwin sowed the seed, 

 and his followers are reaping a plentiful harvest. 



