PLANT HYBRIDIZATION BEFORE MENDEL 171 



nature that their operation, in all combinations is to be recognized by a 

 character in common. 



"Both of these forces, are, however, of different kinds, and follow 

 different laws." (p. 289.) 



Gartner did not realize, in spite of Sageret's experiments, that 

 some individual characters of a parent might be found to domi- 

 nate in a cross and others not. 



"The laws of hybrid types orient themselves," he says, "not toward 

 the individual organs of plants — do not apply to a single part, e.g., 

 stems, leaves, etc. — but are applicable rather to the inner natures of 

 species. The organs which determine the types of hybrids must therefore 

 be investigated and compared in their totality and in their natural 

 interrelationship. For the most part, the peculiarity of a hybrid expresses 

 itself in its entire aspect; only in this respect the flower is most fre- 

 quently and plainly distinguished above other parts of the plant." 

 (p. 251.) 



We do come, however, upon a form of utterance that is some- 

 what singularly Mendelian in character: 



"in the formation of simple hybrids, as in sexual reproduction in gen- 

 eral, two factors are active. This unlikeness of activity, flowing from 

 the specific difference of species, expresses itself through the more pro- 

 nounced or the weaker manifestation of the individual paternal characters 

 in the different parts of the hybrid. Whether the total nature of the 

 species and its formative impulse determines the direction and form 

 of the type, or whether the individual parts of plants have a special 

 influence upon the modifications, may not be determined without further 

 investigation." (p. 257.) 



Gartner made some crosses with corn and with peas, to deter- 

 mine the question of the immediate influence of the pollen upon 

 the character of the seed. In corn he got no results, because of 

 crossing white corn with red, in the case of which latter, the color, 

 being due to the skin or pericarp, does not show itself until the 

 following season. Because of the importance of the later genetic 

 results with Pisum and Zea mays, it will be of interest to follow 

 in some detail Gartner's work in the crossing of plants of these 

 two species. 



The following comment is made upon Knight's experiment with 

 peas : 



"Th. Andr. Knight, in the year 1787, instituted experiments with Pisum 

 sativum fructo-albo (Common White Pea) and P. sativum fructo-cinereo 

 (Grey Pea), which were first made public in the year 1799, concerning 

 which he noted that the pods obtained from these artificial fertilizations 

 were not markedly different from those of the ordinary seed capsules 

 of this variety {Pisum album) ; from which he derived the conclusion 

 that it was probably true, that the outer hull of the seed of Pisum, as 



