A MEDLEY OF PUMPKINS. 123 



sorry if any one who had heard that paper were to go away with the imprussion — I am 

 sure Professor Bailey would not wish to give that impression — that because of the great 

 complexity of the results given by crossing the squashes and pumpkins and allowing 

 their offspring to cross and the difficulty of classifying the offspring so produced, that 

 therefore such a case was contradictory or in any way beyond the scope of Mendel's law. 

 There is no reason so far as I can see to suppose that. If I had time, I could give you 

 a number of cases that we do know are not included in the scope of Mendel's law, but 

 such a case as this, on account of the great diversity of the offspring, is no evidence 

 whatever that Mendel's law does not apply, for the following reason: Mendel's law in 

 its original form is dealing with a statement of the results obtained with hybridization 

 of simple characters. For instance, you cross together the green pea and the yellow 

 pea; the germ cells of the hybrid will form themselves purely yellow or purely green. 

 We are dealing with single characters that were put in with the parents. But Mendel's 

 law deals with a more complicated, and, to the practical man, far more important group 

 of cases than that, where the parental characters that are put in are not simple, and 

 cases in which the hybrid when it comes to form its germ cells does not form the 

 parental characters simplv, but divides those parental characters into what, for the want 

 of a better term, we call their components. For example, the color of these squashes 

 and pumpkins. There is not the slightest doubt that these in other cases would not fol- 

 low the simple rules of Mendel's creation. For example, these colors may consist not of 

 one simple character, but six or eight or ten or more component characters. The shapes 

 of the squashes again in all 'probability consist of at least six or eight component char- 

 acters. When you come to observe that each plant that you obtain can only take one 

 of each of those components from one parent and one from another, you may have com- 

 binations of an immense number of different entities taken two together, so that the 

 complexity reaches a degree that is always beyond the reach of experiment. We cannot 

 infer from those facts that Mendel's law will not apnly. It is simply that the enormous 

 areas which must be under cultivation when we are dealing with such an immense number 

 of characters make it practically impossible to draw any conclusions. One word with 

 regard to the point of the cytological investigations that were told of previously. I am 

 afraid there is a little difficulty there for this very reason in regard to the complexity of 

 character; there is a little difficulty in the way of ever hoping to analyze ultimately by 

 the microscope the characters in the way that Mendel's law teaches us to believe they 

 might be analyzed. Because it is very true that in Ascaris and in a number of other 

 forms referred to we have reason to believe that the chromosomes of the father 

 plant and mother plant side by side represent blocks of parental characters, that is 

 not enough to help us to trace out ultimately the different parental forms of gametes. 

 To do that you would have to have narticles representing each parental character, not 

 merely the whole block of chromosomes representing the father plant and the mother 

 plant; you would have to have fragments representing each of the constituents of the 

 father and each of the constituents of the mother, and they would again combine in the 

 various combinations that we must expect. Complexity itself is no bar at all to the 

 application of Mendel's law. 



With regard to one point that the last speaker made; he said that Mendel's law is 

 possibly a thing of small range of application, or, at all events, cannot be asserted to 

 be of universal application, and consequently it may apply to comparatively a few things. 

 It may be of interest to those who are not perfectly acquainted with those investigations 

 if I just briefly run over the kind of characters that have been shown to follow Mendel's 

 law. For instance, there were Mendel's seven original characters, shape of plants and 

 characters of seeds and pods, carried into several details; then there are the animal 

 cases; we know that it applies to the shape of the combs of fowls, to the extra toe in 

 several races of fowls, we know that it applies to the colors of fowls; we know that in 

 mice it applies to the curious waltzing habit of the Japanese mouse, that character in- 

 volving, we may say, almost mental attributes. We know it applies to the whole series 

 of colors into which the whole series of rats has been broken, and to, I may say, twelve 

 or fifteen different colors in plants. I think it is not too much to say that it applies to 

 almost every case where the test has been possible of application. 



N. L. Britton: The fruit of Cucurbita was the subject of experimentation. Even in 

 the wild species of Cucurbita there is a very great diversity of form and size of fruits, 

 as is well known, and I think it is possible that that might have lent difficulty. 



