THE SPERMATOCYTE DIVISIONS OF THE LOCUSTIDÆ.

BY C. E. M’CLUNG.

With Plates VII, VIII, IX, and X.

I. Introduction.
II. Methods.
III. Nomenclature.
IV. Observations.
(a) General Structure and Form of the Testes.
(b) The Spermatogonia.
(c) The First Spermatocytes.
(d) The Second Spermatocytes.
(e) The Spermatids.
V. Comparisons and Conclusions.
(a) Nomenclature.
(b) The Spermatocytes of the Acrididæ and the Locustidæ.
(c) Formation of the Tetrads.
(d) The Spermatocyte Divisions.
(e) The Accessory Chromosome.
(f) Individuality of the Chromosomes.
(g) Nucleoli.
(h) Rest Stage.
VI. Summary.
VII. Bibliography.