. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. CHROMOSOME COMPLEX OF SPERMATOCYTES. 307 Regarding the enumerations I would say that much confidence is reposed in those of the spermatocyte elements, but that there is less certainty attending the figures derived from the sperma- togonia. This is due to the fact that the latter cells are relatively small and the chromosomes very large, so that the elements are not well separated and clear. There is no fusion of the chromo- somes in the metaphase, but they are long and sinuous and their limits hard to discern. In general, th
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. CHROMOSOME COMPLEX OF SPERMATOCYTES. 307 Regarding the enumerations I would say that much confidence is reposed in those of the spermatocyte elements, but that there is less certainty attending the figures derived from the sperma- togonia. This is due to the fact that the latter cells are relatively small and the chromosomes very large, so that the elements are not well separated and clear. There is no fusion of the chromo- somes in the metaphase, but they are long and sinuous and their limits hard to discern. In general, then, it was found that for the family the number of chromosomes in the spermatogonia is 23 and in the first sperma- tocyte 12. Exceptions were found in Hesperotettix which has 23 in the spermatogonia and 11 in the first spermatocyte; and in Mcnniria which has 23 in the spermatogonia and 10 in the first spermatocyte. Careful study revealed the fact that the exceptions are only apparent, and that the reason for the deviation from the family character is due to unusual associations of the sperma- togonial chromosomes in the spermatocytes. This is brought about by the action of the accessory chromosome which here gives further evidence of its highly important character. It will be well to outline the history of the chromosomes in these genera separately and then refer to the principles of association involved later. 2. The Cliroinosomcs of Hesperotettix spcciosns. It is not my intention to discuss the whole group of chromosomes in this species, but merely to give the history of the most strongly marked element. I hope subsequently to make a careful detailed study of the germ cells of the various species of this genus to establish the relations of the entire complement of chromosomes, but at present that is not possible. If we examine the spermatogonial mitoses of this species we find that the chromosomes are of the usual rod-shape type, but among them there occurs one that is peculi
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