TH"-. II. MoNTi, oMKKY, IK. 



form- a inaK- il" nt fertili/ed, a female if fertili/ed; under the 

 hypothesis the female tendency .-hoiild In- derived from the 

 spermato/oou- -"a rednctio ad absurdnm; for tin- male i- derixed 

 from an unfcrtili/ed e^g which has by tin- hypothesis eliminated 

 the female tendency." 



\.i\\ lin (ig nd Boring (19071 anal} /rd tin- phenomena of 



the allosomes in Hemiptera and Colcoptera respectively, and 

 J..rdan (1908) in an orthopteran. all comparing chromosomal 

 numbers in the- female and male cells, and all inclined to regard 

 the allosomes .,- -ex-determinants. Morrill (1909) found that 

 in Prole nor and other species all the cleavage cells of one indi- 

 vidual have either thirteen or fourteen chromosome^, /. e., all 

 either a Dingle allo-ome or a pair, cmiformalile with \\'il>on's 

 re-ults on the germ cells. 1 



l'a\-ne (1909) has accepted Wilson's views of a qualitative 

 -ex-determination by allosomes; while von Baehr (1909), in dis- 

 cussing the subject at length, is inclined towards the quantitative 

 explanation. \\"allace (1909) concluded that in Ayleua some 

 rmatozoa ha\-e two allosomes, others have none, and argued 

 that a male would result when an ovum is fertilixed by a sperm 

 with the>e two elements; it should be noted, however, that the 

 different describers of aranead spermatogc-nesis have reached 

 qnile eonllii ling results. 2 



l!ali/er i too*)) on echinoids, drew attention to the occurrence 

 of allo-ome- (idiochrosomes) in the female line, though he studied 

 the rhro-oinoine- only in the pronuelei and cleavage cells, inn 

 in the -ro\\ih period of the ooc\ie-. ' We distinguish accord- 

 ingly two types of eggs: some with and some without an 

 unpaired element. The chromosome number i> in both cases 

 ei-liieen. Therefore, \\ e miiM conclude that the unpaireil chromo- 

 some in l lie egg type \\ here il is \\ anting is repre-enied by a rod- 

 shaped element. The sperms al\\a\s \\ith eightei-n elemeni> 

 are all alike. According to the discoveries on insect-, it is not 

 improbable that the determination of sex, which \\ould lie with 

 the female, is connected with this difference of the egg nuclei." 



'Sonic writers ha '. > Prolenor-lype," evidently 



rant that the spi-m. ia 1.1 tlii- lim u;i- Kitlicr lully dea nln-,1 l,y im- 



(1901) some years before \Vil-mi |ml.li-ln-<| liis stmli 



the papers m \\ Ben .nui IU\M-II. 



