FERN GROWING 133 



one to three thousand four hundred into each. The problem 

 is to determine the probability that three numbers drawn 

 haphazard from each box will give the three highest from 

 each." Now if we apply this same reasoning to what has 

 been done in multiple parentage, it seems equally certain that 

 these varieties have not been raised haphazard. 



The same results have followed each experiment, so that 

 instead of this probability being confined to one case, we 

 have every separate experiment to bring into the calculation. 

 This reasoning may not be usual with Botanists, but it is 

 mathematically correct. How many microscopical observations 

 have been considered to have proved certain facts, and yet 

 how many of these facts have had to be discarded on account 

 of subsequent microscopic investigation ? It seems to the 

 author that microscopic research may not succeed to a remote 

 decimal of the truth with any more certainty than by 

 mathematical reasoning in such difficult cases as those we 

 are now considering. Watching the various movements in 

 the impregnation and germination of Ferns, which must be 

 so much hidden by the folds of a cluster of prothalli, and 

 also in keeping them alive and in health during such a severe 

 trial, and being fortunate enough to be able to examine that 

 one prothallus in a thousand that was able to produce multiple 

 parentage, is almost like the calculation of an eclipse of the 

 sun, from the three bodies moving through space at different 

 speeds, in order to arrive at the exact time when all three 

 will be in one and the same straight line. It may be done, 

 and accomplished satisfactorily by one of our specialists ; but 

 the probability of being able to examine the identical pro- 

 thallus whose female cell is about to receive sperms from 

 several other prothalli is so remote that but few microscopists 

 will venture on such an investigation. 



The mode of reproduction varies with different animals 

 and plants. In the higher classes of animals almost perfect 



