FUNCTIONLESS GAMETES 



457 



sometimes have a mitotic or semi-mitotic meiosis on the female 

 side, have a high degree of pairing on the male side. In the 

 Hieracmm, which is triploid, five trivalents may be formed ; in the 

 Poa, of which triploid and tetraploid forms occur, trivalents and 

 quadrivalents are frequent ; in the Antennaria species, some of 

 which are hexaploid or dodecaploid, nearly all the chromosomes are 



Fig. 133. — Spore-formation in the sexual four-spore (A- J) and the 

 non-sexual two-spore (K-R) race of Camarophyllus virgineus. A, 

 paired, diplophase nuclei. B, C, their fusion. D, zygotene. 

 E, metaphase of the first division. F, anaphase. G, interphase. 

 H, telophase of second division. J, migration of the four nuclei 

 into their pouches. K, single nucleus. L, prophase. M, N, single 

 division. O-P, spore nuclei formed. R, their migration. (From 

 Rosenberg, 1930, after Bauch, 1926.) 



associated in bivalents or multivalents. Taraxacum Nordstedtii 

 similarly forms multivalents. These observations not only reveal 

 the potential dissociation of behaviour on male and female sides. 

 They also show that these species are autopolyploids and therefore, 

 even where they have an even number of chromosome sets, and 

 the pairing chromosomes are ahke, they must have an irregular 

 meiosis and be sexually infertile. In other words, although there 

 is no evidence of their hybridity there is evidence that abnormality 



