108 THE ORIGIN OF GYNANDROMORPHS. 



large number of chromosomes, nor is it probable that a case involving 

 sex-linked factors will soon be found. 



Some of the older writers seem to mean by hermaphroditism the 

 presence of complete sets of both male and female organs, the two 

 systems superimposed on each other. The rather mythical accounts 

 of such cases do not call for serious comment. 1 Where the evidence 

 is anatomical and given by trained observers it appears that some, 

 perhaps all, cases are mosaics rather than "hermaphrodites" in the 

 sense of double-sexual individuals. In other words, parts of one and 

 parts of another system are found in the same individual, replacing 

 each other locally. If this interpretation turns out to cover certain 

 cases the theory of chromosomal elimination will suffice at least as a 

 formal explanation of such human abnormalities. Since the human 

 species is both from the genetic and cytological evidence XX hi the 

 female and XO in the male, the same mechanism exists as is found in 

 Drosophila, and if the theory of chromosomal elimination applies here 

 also, human gynandromorphs would be expected in practically all 

 cases to begin as female (XX) and produce male regions by eliminat- 

 ing one X. An examination of the literature shows hi fact a consider- 

 able preponderance of the cases showing more female than male regions, 

 but the evidence is too uncertain to give any serious weight to it. 



IS CANCER A SOMATIC MOSAIC? 



Into the difficult and obscure question as to the cause of cancer it 

 is not our business to enter, but a suggestion made by Boveri (in 

 1902 and 1914) calls for brief notice, since he appealed to a process 

 akin to chromosome elimination as a possible explanation of the 

 phenomenon. Boveri suggested that an imperfect or irregular division 

 of the chromosomal complex might in certain cases produce combina- 

 tions through loss of specific chromosomes that caused the different 

 cells to run wild, so to speak, in the sense that factors that normally 

 inhibit the rate of growth or the suppression of growth in relation to 

 the cell environment are lost. In support of such a view he appealed 

 to occupational cancer-growth, where cancer develops in parts of the 

 body most subject to mechanical injury or pressure. It is known to 

 students of embryology that compression of a dividing cell may inter- 

 fere with the normal distribution of the chromosomes to the daughter 

 cells. At present, however, reference to such possible sources is too 

 uncertain to be of great value, for there are no instances where irregu- 

 larities of this kind are known to give rise to prolific growth processes. 

 The cancer-like or tumor-like growth shown by a mutant race of 

 Drosophila, discovered by Bridges and described fully by Stark, has 

 not been shown to be associated with abnormal distribution of the 



1 See comment by Dr. H. L. Ganigues, Medical Record, 1896, p. 725. 



