338 Proceedings of the Ohio State Academy of Science 



might agree witli the conchisioii, hut since we have exactly the 

 opposite condition in the i'teridophytes the hypothesis is proh- 

 ably incorrect even for the cases where it seems to fit. And 

 certainly the production of some unisexual individuals among 

 the abnormal gametophytes developed from the sporophyte, 

 notwithstanding the fact that both sex tendencies were present 

 and should have produced hermaphrodites, clearly points to the 

 simpler explanation, namely, that the unisexual condition in 

 both cases was brought about in the same way. To my mind 

 the experiments indicate just the opposite from the conclusions 

 drawn. If all the diploid individuals had been hermaphrodite 

 the case would have been somewhat stronger. Even then the 

 hypothesis would not necessarily follow that male and female 

 hereditary characters were separated by the reduction division. 

 For reduction might be merely the cause of the latency of one 

 tendency or the other in chromosomes possessing both qualities. 



As stated, in the homosporous pteridophytes the haploid 

 gametophvtes are mostly hermaphrodite, so it is certain that no 

 sexual tendencies are segregated in reduction. Now is it not 

 self-evident that in haploid hermaphrodite gametophytes at least 

 so far as the evidence goes at present, both maternal and pater- 

 nal sets of chromosomes have similar hereditary characters? 

 Are not sexual peculiarities for the most part simply modifica- 

 tions in develoj^ment of the general hereditary characters of the 

 body which may produce a male-like, a female like, or a neuter- 

 like type of structure depending on certain conditions of in- 

 ternal or external environment. Even Wilson, who has prob- 

 ably gone farthest in finding a specific difi:'erence between male 

 and female insects, says that male and female are but relative 

 terms. One need only recall the influence of emasculation on 

 some of the higher animals to be convinced how important some 

 more or less remote influences may be in determining the de- 

 velopment of secondary sexual characters. 



There are few plants that are strictly dioecious. In the 

 willows and mulberries for example the sporophytes are fre- 

 (|uently bisphorangiate. In all such plants therefore the heredi- 



