150 TRANSACTIONS AND PUOCEEDINGS OF TllK [scss. i.xvi. 



In 1895 the writer was not sufficiently sanguine to 

 believe it possible that at present the embryo would be 

 found to arise in any case from such a spore-mother-cell. 

 Only its formation at some time in the past from a spore- 

 mother-cell was spoken of, because the facts of develop- 

 ment at that time known seemed to point to its origin from 

 at least a few cells. 



And, moreover, everything then seemed to go to prove 

 the production of the " sexual organs," i.e. the germ-cells, 

 by the embryo itself. Such was the belief of almost every 

 embryologist, and there appeared little or no reason for 

 doubting its correctness. 



The effect of these two factors was to bar further 

 progress in that direction, at anyrate for a time. In face 

 of the apparent facts, I confess that it was impossible to 

 foresee how the formation of the spore-mother-cell was 

 effected, with the natural result that only its former exist- 

 ence, i.e. in past times, was suggested. Moreover, there was 

 not the slightest suspicion in my mind or Murray's that 

 the germ-cells had anything to do with the matter. 



It is possibly a humiliating confession to make, but it 

 is quite true, that I was never able to conceive how Nature 

 could carry out this formation of a spore-mother-cell and 

 of the embryo from the latter, until my researches had 

 revealed how she actually accomplished it. No one could 

 have been more astonished than the writer at the 

 revelation. Never had it for a moment been imagined 

 that the germ-cells themselves would play the part they 

 actually do in the life-drama of an antithetic alternation of 

 generations. Only when the work was practically complete 

 and ready for publication was it seen that the missing link 

 in the alternation had been discovered in the primary 

 germ-cells and in the epoch of their formation. 



I hardly feel called upon to prove that the primary 

 germ-cells do represent spore-mother-cells. If each of 

 them were to undergo a reduction with the subsequent 

 production of four "spores," and if then each animal 

 spore were to develop into an organism, we should have 

 the exact Equivalent of the gametophyte of one of the 

 higher plants. 



Instead thereof they remain together, and only one 



