238 WM. REES B. ROBERTSON 



and tetrad-rods, if the rods involved be short (8's, 7's, and 5's) — 

 may be considered identical with the body or main part of a 

 Syrbula no. 11-, 10-, 9-, 8-, 7-, or 5-tetrad of this stage. As 

 the metaphase passes into the anaphase and the process of dis- 

 junction approaches its end, the perpendicular-ring portion in- 

 creases at the expense of the horizontal portions (figs. 182, 183) 

 until, in the anaphase, the shorter members of a compound 

 (5's and 7's, fig. 181) separate, leaving the longer members still 

 attached, their horizontal rings changing to crosses (figs, 181, 

 182c) and finally to rods just before the completion of the dis- 

 junction. The circular space enclosed by the perpendicular ring 

 in these compound tetrads becomes, in the anaphases of the first 

 maturation division, the space between the V-shaped daughter 

 chromosomes resulting from division of these bi-tetrads. Since 

 it is the same space as that seen in parasynapsis between the 

 two gaping-apart strands of these compound chromosomes, we 

 conclude that the first division must be reductional. 



Turning now to the literature involving V-chromosomes of 

 these stages (synapsis and reduction), I find figures of prophases 

 that are comparable with what I have here described for Chorthip- 

 pus. In the lily Gregoire's ('99) figures 6, 8, and 12 resemble 

 my 'j' stage (fig. 174). His figure 19a is identical with my figures 

 183a and 183b, and figures 19b and 19c are similar to my 7-1 1's 

 and 5-9's in figure 181. The result of the division, if continued, 

 would have been an equal-armed V going to each pole (his 

 figs. 19b and 19c), each in turn split longitudinally in preparation 

 for the second maturation division (see my figs. 184-186). In 

 Tomopteris (Schreiners, '06a), which has many V's, I find one 

 of the best series of such chromosomes. Their figures 34-36 

 correspond to my stage '^,' figure 38 to 'j,' and figures 39, 49 to 

 late '/c' or early 'L' Upon examining their figures it will be 

 noticed that the perpendicular ring of the middle region increases 

 at the expense of the more distal portions until there is a break- 

 ing through of the short arm and finally of the long arm of the 

 V (figs. 53, 56, .57, etc.). Frequently the long arm of the V 

 forms a cross at the junction with its mate, similar to that of 

 my figure 183. In the anaphases (figs. 58-60) the V's in their 



