PLATE VIII 



Secondary Pairing at Meiosis in Polyploids 



Fig. I. — Cydonia cathayensis (Pomoideae), 2n = 17. X 2500. 



Fig, 2. — Pentstemon IcBvigatus, in = 96 = \ix. 



Fig. 3. — Dahlia coronata x D. coccinea, 2w = 32 = ^x. x 2000. 



Fig, 4. — Second metaphase in Prunus cerasits. 19 + 13 chromo- 

 somes. 2n = 32 = 4Ar {cf. D., 1928), 



Figs. 5-7. — /Esculns carnea and its parents, X ca. 3000. 



Fig. 5, M. Hippocastanmn {^x = 40), Fig. 6. .'E. carnea 

 (8;ir = 80). Fig. 7. ^^. Pavia {^x = 40). 



Figs. 8 and 9. — Dahlia .variabilis, the same plate at two focuses. 

 2n = 64 = Sa'. X 2000. 



Figures reproduced by kind permission of Mr. A. A. Moffett (Fig. i), 

 Mr, L, La Cour (Fig, 2), Miss M, B. Upcott (Figs. 5, 6 and 7), and Mr. 

 W. J. C. Lawrence (Figs. 3, 8 and 9), All from medium Flemming 

 — gentian-violet sections. 



