J. W. H. Harrison 5 



On the Wholly Male Broods. 



In my experimental facts, tabulated above, an extraordinaiy and 

 striking series of phenomena appears before our eyes. We see a 

 suggestive chain of broods, commencing with those perfectly normal 

 in their sex proportions, and passing through broods containing males 

 and intersexes to those comprising males only. Furthermore, in-e- 

 spective of any bizarre way in which a given brood may be built, that 

 yielded in the reciprocal cross is, except that in two or three cases* the 

 number of females is in excess, precisely what one expects in families of 

 normal parentage. 



Nor must it be supposed that these observations refer merely to 

 certain selected families ; it is not so. We are not here concerned with 

 phenomena of family value, for whenever these crosses are made, pro- 

 vided that the same species and the same sexes are involved, the results 

 are identically the same. And in some instances the number of such 

 broods reared reaches a very high total, verging upon the outcome of 

 over a hundred different pairings. 



Even a cursory inspection of the sex numbers reveals the significant 

 fact that, no matter what the constitution of the remainder of the brood 

 is, in the case of the primary hybrids the males make their appearance 

 in their accustomed numbers. They seem not to be affected in the 

 slightest by the disturbing cause, whatever it may be, bringing into 

 being these remarkable eccentricities. 



The females, however, appear, in some anomalous and unexpected 

 fashion, to have been urged progressively toward maleness, culminating, 

 in extreme cases, in the tilting of the entire female organism into the 

 male condition. 



Concisely, the following statement enables us to gain a clearer idea 

 of the stages whereby the final result is attained, and incidentally shows 

 that, even before the actual sex is put in a state of unstable equilibrium, 

 the interference with the full sex powers has already been initiated. 



(1) Crosses with both sexes partially fertile. 



Poecilopsis pomonaria female x Lycia hirtaria male. 

 P. isahellae female x P. pomonaria male. 

 P. pomonaria female x P. isahellae male. 



(2) Sexes in the usual proportions : ova deposited hut never hatching. 



Poecilopsis isahellae female x Lycia hirtaria male. 



^ One very often rears a great excess of females in wild .broods of the various species of 

 the genus Poecilopsis, and occasionally in Nyssia. 



