It will likely be observed that there’s a certain catholicity in these conclusions at which Cuénot arrives, and in the current unsure state of our data on many vital points it might be wiser to not take too slim a perspective in regard to what elements determine the sex of the individual. These are a number of the principal info that seem to point out that the sex of the person is predetermined within the egg. In respect to the prevalence of the 2 kinds of spermatozoa, Beard brings together quite a heterogeneous assortment of info. OF the numerous writers upon this topic, some have approached it with such an imperfect and narrow acquaintance with the details that their contributions are of no curiosity to the scientific student; while other writers have allowed some minor generalizations to assume such prominence that their papers are of little worth in themselves. If that’s the case his concept can have little or no if any worth, since your entire conception on which it rests, namely, the separation of the male and the feminine eggs at one division, is rendered valueless, I believe, by the assumption that after such a factor has once taken place a feminine cell might in the next era give rise to male eggs.
If the female aphid develops from a female egg (the polar our bodies of that are on Beard’s principle additionally feminine), we can perceive why in the following generation she must give rise to feminine eggs, but why should males ever be again produced? The sex of the person that develops from a non-fertilized; i. In placing contrast to the overall conclusions of Cuénot, Strasburger, Lenhossék, and of Born there are two more moderen theories during which an try has been made to explain intimately how the sex of the person may be decided within the egg. From the proof Cuénot arrives at the next general conclusions: He thinks that in the great majority of animals the sex is determined within the egg and at newest when the egg is fertilized. He arrives at the conclusion that the sex of the higher animals and plants is set in the egg. It’s the egg alone that determines the sex. He believes moreover that it is the egg and not the spermatozoon that determines the sex of the person.
In different animals, as in the rotifers and in the social hymenoptera, the spermatozoon seems to have a figuring out influence. In these circumstances, although the type of the spermatozoa is similar for the two varieties, there appears to be a difference in the quantity of the chromatin materials. The discoveries of McClung, Montgomery and Sutton on this connection point out that there are two sorts of spermatozoa, and McClung has urged that this distinction is linked with the determination of sex; however there may be nothing greater than the supposition that this could also be so to go upon at current. Whenever we discover lengthy series of parthenogenetic females, as within the aphids, developing from and also producing parthenogenetic eggs, Beard supposes that only feminine eggs have been produced in the ovary, and that the male eggs, which have appeared in a single at the very least of the primary generations of the germ-cells ‘should be either delayed in their ripening or suppressed.’ Here we meet with a paradox that’s so patent and touches such a elementary point of Beard’s concept that it’s more than shocking that he has mentioned nothing about it.
On the entire it does not seem that Beard has supplied a really convincing theory as to how the willpower of the sex of the individual is accomplished. Whether the individual is a male or a feminine relies upon solely upon whether or not a male or a female egg has been produced. 1. The sex of the person is determined in the egg before fertilization. Whether it would have turn out to be a male or not, could not be determined; for it is said that the queen sometimes makes a mistake and deposits a worker egg in a drone cell. This division is comparable to the one in the egg-sequence when the polar our bodies are given off, so that each group of four spermatozoa corresponds to a female egg and its three female polar our bodies, or to a male egg and its three male polar bodies; however within the circumstances of the spermatozoa the people are purported to be without sexual qualities. An early separation of the spermatogonial cells into male and feminine occurs. Furthermore Beard’s assumption, that the separation of the male and the female eggs occurs at the time when the reduction in the variety of the chromosomes takes place within the egg, is pure guess-work, and not very good guessing both, for sure recent work signifies that the discount within the number of the chromosomes includes a course of that may haven’t any conceivable connection with the separation of the male from the feminine parts of the egg.