No. 605] 



NUCLEUS AND CYTOPLASM 



by and $ are proved to bo also ('.,ual. Shull's coiitoii- 

 tion for the participation of the cuiz- (■\-1(»i)la>iii rc>ls en- 

 tirely on the maternal cliai-actcr of llio tir>l cuu-uvnci-a- 

 tion. Tliese eggs wei-e inatm-cd. >iiico tlu" inotluT was 

 homozygous in the cliaractcrs. iimlcr llic iiilluriicc ot' the 

 like chromatic contributions of iior jtarciits: tlic liyl)i'i<l 

 mother matured hers under the influence of llic m/liL-f 

 chromatic contributions of her parents and showed the 

 l)artici])ation of lier paternal chromosomes only in the 

 behavior of her eggs. The ])ecnliaritles of the ease lie 

 not in that we are dealing with a (•> topla-mically deter- 

 mined character, as Shull contend-, bnt In (I) the fact 

 that the characters are exhibited only by females C2) in 

 the fact that the characters are egg-characters, which 

 places segregation one generation farther away from the 

 original cross. 



The case is quite analogous to the case of the inherit- 

 ance of red pericarp color in corn, which, allhouudi a 

 ''maternal character," was shown to Mendel ize by Ijock 

 ('Of)). Tt is also comparable to the eg- (-haracter "uni- 

 bivollinisnr' in silk moths, which ('astle ('10) i)roved 

 from Mi» M.-(VackcnV data to be a ^Mendelian character. 

 'I^Ik se .-ax'- will be dixMi-eil more fullv in later para- 

 graphs. 



Shull's concln-lon that c>topIa-m .Icterniine- e-u and 

 larval character^ i-. 1 b.^licNe. nniieces>aiw. It has been 

 shown that chara.'t. r- c\liibited oid\ b\ feniah- and only 

 in the eu- )nay b,- , (|ual]\ determined both in the egg and 

 in tile speiin. The >]»erm cont ribut iini being predomi- 

 nantly chromatic, and tiie chromosomes being the ac- 

 cepted carriers of tlie determim'i-> of other characters, it 

 is to 1)e concluded that the determiners for the characters 

 investigated by Simll are aUo to be -oiiuht in tlu' chromo- 



