Cardiff : Synapsis and reduction 29o 



possible the evolution of complex higher organisms/' If, as is 

 generally admitted, the chromatin controls the metabolic activities 

 of the cell, it would seem that the above theory is not without 

 considerable foundation. The familiar fact, that an offspring more 

 often possesses certain characters of the one parent to the exclu- 

 sion of the other, would indicate that it is the chromatin of the 

 latter that is controlling the physiological processes of the organism. 



Nor are we without evidence that the maternal and paternal 

 chromatin remains distinct during the sporophyte phase. Black- 

 man ('98), Chamberlain ('99), and Miss Ferguson ('04) have shown, 

 in Punts, that the maternal and paternal chromatin do not fuse 

 with the union of the gametes. Murrill ('oo) observed the same 

 behavior of the gametes in Tsuga, and similar results have been 

 reported for a number of other gymnosperms and in Onoclea by 

 Shaw ('98). Dublin ('05^) reported a similar phenomenon in 

 Pedicelli)ia, a bryozoan. But it is to the work of Moenkhaus 

 ('04), of Herla ('93), of Haecker ('95^), of Ruckert ('95), and of 

 Zoja ( ? 9S) we must turn for the best evidence on the independence 

 of the paternal and maternal chromatin. Moenkhaus, in working 

 with hybrid fishes, found that the maternal and paternal chromatin 

 remained distinct until the third division in the embryo. He was 

 able to follow this with especial clearness owing to the fact that 

 the chromosomes of one parent, Fundiilns, were much larger than 

 those of the other parent, Menidia. Haecker and Ruckert in 

 Cyclops, and Herla and Zoja in a hybrid Ascaris have also found 

 that the chromatin of the two parents retains its identity through 

 several divisions in the embryo. Since it is conclusively proven 

 that the maternal and paternal chromatin retain their identity 

 through several cell-generations, there is no reason why it should 

 not be expected to do so through many generations, in fact, the 

 latter seems highly probable. 



If the above is true, the explanation of synapsis is that it is the 

 end-result of fertilization. Thus the two phenomena of fertiliza- 

 tion — stimulus to growth and mingling of ancestral characters — 

 are quite widely separated, the former coming at once with the 

 union of the gametes, and the latter with synapsis. The idea — 

 not new — that the offspring is not the offspring of the parents, but 

 of the grandparents, would find support in the results obtained. 



