2 The Ohio Journal of Science [Vol. XVII, No. 1, 



It may be granted that the cytological work of the past 

 fifteen years has estabhshed an undoubted connection between 

 chromosomes and sex. One may even magnanimously neglect 

 to point out that in some cases, for example, in the phylloxerans 

 and probably the rotifers, the sex-determining event, as shown 

 by differences in the size of the eggs, precedes the differential 

 behavior of the chromosomes, and that the chromosomes are 

 therefore not players, but pawns. It may be admitted that the 

 experimental work of Baltzer, Gates, Lutz, Stomps, and others, 

 has fixed upon the chromosomes the responsibility of producing 

 certain hereditary features of the organisms they studied. 



Yet, after making all these admissions, it is possible to accept 

 as demonstrated certain facts which plainly indicate an influence 

 upon hereditary processes, of something else than chromosomes. 

 It is rny purpose first to point out a few of these facts; and 

 second to show how we may cherish this evidence, without 

 spewing the chromosomes out of our mouths, like the angel of 

 Laodicea, and likewise without straddling. 



Among the foremost evidence of the importance of cyto- 

 plasm in heredity is that derived from cases of inheritance only 

 through the mother. Inheritance only through the mother is 

 in strong contrast to one of the earliest evidences in favor of the 

 nucleus as the bearer of hereditary factors. It was long ago 

 pointed out that father and mother shared equally in fixing 

 the nature of the offspring; but that the spermatozoa carried 

 little or no cytoplasm, while the egg was, from the standpoint 

 of volume, chiefly cytoplasm. The chief difference between egg 

 and sperm is that the former is lumbered down with a mass of 

 passive cytoplasm and yolk, from which the sperm is practically 

 free. When, then, we find a case of inheritance only through 

 the mother, there is left little room for any conclusion but that 

 this inheritance depends upon the cytoplasm of the egg, or upon 

 something included in the cytoplasm. 



The facts in one such case are these. In the old-fashioned 

 four o'clocks of grandmother's garden, Mirabilis Jalapa, there 

 is a variety named albomaculata, which has variegated leaves. 

 The structural basis of the variegation is the fact that the 

 chromatophores in the yellowish white patches are not bright 

 green, but more or less blanched. The amount of green and 

 white varies greatly in different plants. Furthermore, whole 

 branches may be green, other whole branches white. 



