No. 605] NUCLEUS AND CYTOPLASM 



295 



of experiments on a hatching time character has, how- 

 ever, lieen carried tlirough tlie F., generation and as an 

 illustration sncli a case may he cited in detail. It consists 

 of Miss Mc('racken'> (l!Mi:i) pxi.crim.'nt^ with A\k luoiii^. 

 Castle later (1910) cahed attciitioii to mmmo lan^ l,i \.rv 

 data which indicated that alt liouiili a feiiiaU^-cxliiitilcd 

 character and confined to the egg in its expression, it 

 nevertheless gave evidence of Mendelizing in crosses. 

 Toyama ( '12) concluded that dominance was present, and 

 both of the latter investigators agreed that tlie males, al- 

 though unable to exhibit the character, gave cx idcncc hy 

 their genetic behavior of having an eiiual detci-niiiiat i\ c 

 influence with the females. The data follows: 



Silk moths lay one batch of eggs, always in tlu" >i'riim. 

 The eggs of some batches hatch out inmiediatcl)-. pio- 

 ducing another brood of larv{P and moths in that >oasoii. 

 The parents of such batches of eggs are hence known as 

 bivoltins. The eggs of other batches do not hatch for 

 twelve months, and since in this way there is but dne 

 brood or flight each season, the parents of such eggs are 

 known as univoltins. If a univoltin female is crossed 

 with a bivoltin male, the s])ring batch is laid as usual and 

 hatches in 12 months. This is just what would have oc- 

 curred if the nn-.tlier had been fertilized by a male of her 

 own Mn-I. WIkmi tlu-o (-2. li;,t.-li. a hyl>rid' hroo<l (Mn.M-(- 

 whi.-li lay their c-- l.atrhr. ininicdiatelv but tlic univoltin 

 "•liai'a.-tcr i> a-alii cxhlhitcd in that all of Ww-r arc 

 of tho 12 months txpe. r.nt. thc^" o-u- uo^^ .lilVrr anioiiii 

 tllrlUM^K,- .-1. i. .liMNM, ^^ tlu hohaxior of thr /\u.)te^ 

 whi.'h , iiiriur t'roni th.Mu. Snino of tlu-.- f.-mah- arc 

 bixoltin. laxlnu whlrh doM'lop ininu'diatclx . while 



<.tlu r^ arc nnivoltin. layin- c-u- wliidi hatch tlu' I'ollow- 

 inu' >)M-in-'. Tiio oxprc-.-ioii of the paternal contribution 



The inheritance ol' red pei'icar]) color in corn follows 

 <'xactl\ the same c(nir>e a- that outlined above, with red 

 dominant over white. Tlie Fo embryos must be raised 



