Montgomery finds these rings in _Peripatus_, and realizes the importance of their evidence in determining the planes of division, but places his conclusions upon a much more insecure footing than those founded upon the Orthopteran cells, because of the criterion used in determining which point represents the junction of the paired chromosomes. The diagnostic feature he uses is the linin connection persisting between the “central ends” of the chromosome, which holds them together until the “distal fibers” connect with the centrosomes and cause the rupture of the “central” fiber. Since the whole of his elaborate theory regarding the continuance of the linin spireme is practically a theoretical conception with little basis in observed fact, the value of such proof cannot compare with that furnished by the definitely formed chromosomes themselves in the Orthopteran cells. In view of all these facts, I think it must still be held an open question as to which is the reduction and which the equation division in the Hemipteran spermatocytes, although it is not to be doubted that the probability of the first spermatocyte being witness of the reduction division is much increased when thus interpreted by two independent observers. (_e_) _The Accessory Chromosome._ I have already, in another paper (=19=), taken up a comparative study of the accessory chromosome in different insect spermatocytes, and shall not be obliged, for that reason, to enter into a very lengthy discussion of the subject here. The great interest attaching to this structure, however, compels me to consider the work that has been done since the manuscript of the earlier article was sent in for publication. This review will concern, very largely, the investigations of Montgomery upon a considerable number of Hemipteran species, which are set forth in his paper under the pretentious title “A Study of the Chromosomes in the Germ Cells of Metazoa.” In his first work upon _Euchistus_, Montgomery describes a cell element under the name “chromatin nucleolus” which corresponded so closely to my accessory chromosome that I concluded the two structures were identical. These similarities were, the origin from a spermatogonial chromosome, the integrity and constancy of staining power and position during the spermatocyte prophase, and participation in the division act during metakinesis of a spermatocyte.