136 FERN GROWING 



5th. — That until two of these quarters are brought close 

 enough to each other so as to coalesce, there can be no 

 impregnation. 



6th. — That if two of these quarters have thus been brought 

 together without frond life resulting, each must have had the 

 organs of one sex only. 



7th. — That if afterwards a third quarter is made to coalesce 

 with the former ones, and impregnation then takes place, the 

 last quarter must have had the organs of the opposite sex. 



8th. — That these three quarters having produced five 

 plants, more than a single cell on one or other of these 

 quarters must have been impregnated ; if not, two of these 

 quarters certainly will have contained only the male organs.* 



9th. — That the divisions of a divided prothallus can live 

 more than seven years if unimpregnated. 



loth. — That if three or four varieties have been sown 

 together and some of the resulting seedlings have the pecu- 

 liarities of all the parents, the male sperms will have travelled 

 to a different prothallus. 



nth. — That these last results are not the effect of a 

 previous cross, for two reasons — first, because the resemblances 

 are confined to those varieties sown together ; and secondly, 

 that the seedlings, no matter of how many generations of 

 crosses, if sown singly, will only produce the likeness of the 

 Fern sown. 



There is one question worthy of consideration to which 

 these experiments give rise, it is this, two or more cells on 

 the same prothallus have become impregnated. Will this 

 cause assimilation ? Will the effects produced in each cell 

 become commingled? If so, instead of a cell requiring the 



* As a matter of fact two had only female cells, and only one, male organs. This 

 was ascertained by seeing two plants springing up from one division, three from 

 another, and none from the third, the one which had been placed so as to coalesce 

 with the others. 



