DESCRIPTION OF PLATES 



The figures were drawn with camera lucida, and the magnification multiplied with the aid of a 

 drawing camera, by li or by z, as follows: 



Figs. I, 4, 5 to lo, 22 to 51, 53 to 100, 106 — Zeiss 2 mm., 12 oc. X 2. 



Figs. 2 and 3, 13 to 16, 18 to 20 — Zeiss 2 mm., 120c. X ij. 



Figs. II and 12, 17, loi to 104, 105 to 107 — Zeiss 2 mm., 6 oc. X 2. 



Fig. 108 — Zeiss 2 mm., 6 oc. X li. 



Figs. 21, 52 — ^Zeiss 1.5 mm. 12 oc. X 2. 



The plates were reduced one-half. 



Lettering on Plates 



* = an unpaired heterochromosome. 



hi = the larger of an unequal pair of heterochromosomes. 



/(2 = the smaller of an unequal pair of heterochromosomes. 



Plate I 



Ellychnia corrusca (Fam. Lampyridte) 



Fig. I Spermatogonium, metaphase, nineteen chromosomes. 



Photinus pennsylvanicus (Fam. Lampyridte) 



Fig. 2 Oogonium, metaphase, twenty chromosomes. 



Fig. 3 Spermatogonium, metaphase, nineteen chromosomes. 



Fig. 4 Somatic cell d^, metaphase, nineteen chromosomes. 



Figs. 5 and 6 Synapsis stages. 



Fig. 7 Synizesis stage, spireme type. 



Figs. 8 and 10 Growth stages. 



Figs. II and 12 First spermatocytes, metaphase. 



Fig. 13 First spermatocyte, metakinesis, polar view. 



Fig. 14 First spermatocyte, metakinesis, side view. 



Figs. 15 and 16 First spermatocytes, anaphase. 



Fig, 18 Second spermatocyte, metaphase. 



Fig. 19 Second spermatocyte, anaphase. 



Fig. 20 A pair of spermatids with nine and ten chromosomes. 



■ Photinus consanguineus {Fam. Lampyridte) 



Fig. 21 Ovarian follicle cell, metaphase, twenty chromosomes. 



Fig. 22 Spermatogonium, metaphase, nineteen chromosomes. 



Fig. 23 Synizesis stage, loop type. 



Figs. 24 and 25 Synapsis stages. 



Fig. 26 Growth stage. 



