182 Intracellular Transmission of Characters 



Like the qualities of the vacuoles, those of the chro- 

 matophores must be communicated to the hybrid during 

 hybridization, in a latent condition in the pollen-nucleus 

 of the father. As an instance I mention Raphanus sativus 

 9 X Brassica oleracea $ , Medicago sativa $ x falcata $ , 

 Geum album 9 x urbamim $ , Verbascum phoeniceum 9 

 x blattaria $ . 2Q 



Similar instances can be found in great number in the 

 abundant literature on hybridization-experiments. But 

 science greatly needs a comprehensive miscroscopic study 

 of hybrids in relation to the anatomical structure of their 

 parents. 27 



Still more forcibly and more generally do we feel the 

 necessity for the assumption of a transmission, when we 

 observe the hybrids in the second and following genera- 

 tions. Almost always, when cultivated in a sufficiently 

 great number, some of them revert to the grand-mother, 

 others to the grand- father. The latter ones are so similar 

 that they could be easily confounded with the grand- 

 father. This teaches us that in hybridization, all the 

 characters of the father pass on to the hybrid, where they 

 are present in the latent state only, but that they become ac- 

 tive again in some of its children. All the organs of the 

 protoplasts must therefore be able to draw their active 

 characters from the nucleus. 



In the hybrid, however, the characters of father and 

 mother are equally represented. Especially are both hy- 



26 These instances are from Focke, where more can easily be 

 found. I regret to say that I had no opportunity of controlling the 

 nature of the yellow coloring matter. 



27 The "Comparison of the Minute Structure of Plant Hybrids 

 with that of their Parents, and its Bearing on Biological Problems," 

 by J. M. MacFarlane (Trans. Roy. Soc. Edinburgh, 37: 203. 1892) is 

 still practically the only investigation in this field. Tr. 



