The proof on which Castle rests his assumption that there are two kinds of spermatozoa, in addition to two sorts of eggs, is contained in the next statement: “That intercourse is borne by the egg is proven clearly by the case of parthenogenetic animals, which without the intervention of a male produce younger of each sexes. That the spermatozoon additionally bears intercourse is manifest within the case of animals like the honey bee, for the egg of the bee, if unfertilized, invariably develops into a male, but if fertilized into a feminine.” The finality of the conclusions drawn from these details is in no way above query. There’s one result that Castle cites, which he claims signifies that his assumption that the eggs may present a selective power towards sure of the spermatozoa just isn’t unwarranted. In a number of insects, in Dinophilus, in pigeons, and within the winter eggs of aphids and of daphnids, this has been clearly proven to be the case. It has not been proven that a difference of this type would have any worth in the willpower of intercourse, and even when this had been the case the outcomes don’t conform to the necessities of Beard’s idea, as we shall see presently.
We shall see presently that Castle fails to satisfy this basic query. Whenever we discover lengthy collection of parthenogenetic females, as in the aphids, growing from and likewise producing parthenogenetic eggs, Beard supposes that only feminine eggs have been produced within the ovary, and that the male eggs, which have appeared in a single not less than of the primary generations of the germ-cells ‘should be both delayed in their ripening or suppressed.’ Here we meet with a paradox that is so patent and touches such a basic level of Beard’s idea that it is more than shocking that he has stated nothing about it. If that’s the case his idea can have little or no if any worth, since your entire conception on which it rests, particularly, the separation of the male and the female eggs at one division, is rendered valueless, I think, by the assumption that after such a factor has once taken place a feminine cell could in the subsequent technology give rise to male eggs. He assumes that a male spermatozoon can fertilize solely female eggs, and a feminine spermatozoon only male eggs. Beard appears to take without any consideration that a female egg can give rise to cells that turn into male eggs.
Beard tries to show that there are usually not only two sorts of eggs, but in addition two kinds of spermatozoa that correspond to the two kinds of eggs. Just as there are two sorts of mice in our illustration, white and black, there are two varieties cf sexual people, males and females. Among some teams of individuals, the carrying of a purity ring is a reminder to oneself and others, that they’re training sexual abstinence. In putting contrast to the general conclusions of Cuénot, Strasburger, Lenhossék, and of Born there are two more recent theories by which an attempt has been made to describe intimately how the intercourse of the individual may be determined in the egg. There may be another facet of Castle’s speculation that have to be briefly referred to, since he suggests a means of assembly a problem that’s fatal to Beard’s theory. Allow us to now return to Castle’s concept and see how he tries to make an application of Mendel’s principle to intercourse.
A photographer good friend clued me into the foot-fetish trade and let me know the way much my toes are worth. Castle supposes that in parthenogenetic reproduction the female character dominates over the male, when the two are current together, and that when a separation of the sex-characters takes place it does so at the time of the formation of the second polar body within the egg, and probably on the corresponding state of improvement within the spermatozoon. He arrives at this conclusion in the face of an overwhelming physique of proof to the contrary, for in the good majority of forms all the spermatozoa which might be formed develop in the identical manner and are, so far as we will see, capable of fertilizing the eggs. He arrives on the conclusion that the sex of the higher animals and plants is decided in the egg. His dialogue of the relative number of males and females born in the human race is particularly instructive, however it will carry us too far here to debate the conclusions at which he arrives. An unusual and doubtless degenerate course of occurs within the formation of the worm-like spermatozoon, so that as a substitute of containing the diminished number (seven) of chromosomes it accommodates however a single one.