DroHopli \hi Mchninrfostrr. 



303 



This cross slidiild ;xivc .1 r;ili(i of ;>:.';:.!:1 iC (lie j;c'iio for ciirvod is in 



a clininKisoiiH' oOicr tliaii I\'. I'.nil is a p ■ cliaraclcr widi whicli to c<jii- 



(rast curvtMl since liolli cliaractcrs involve liic wiii^s and tlie douijle re- 

 cessive cainiot Willi cerlainly he liislin^nislied. A few forms aitpcared, 

 liowevei-. wiiicli I took to he cnrNcd lient. Conidinf: tlio douJ)Ift recessive 

 with curved and l>ent a ratio of i> to 7 siiould result. Tlio tahle gives 

 apitroxiniately this ratio and a teidati\e conclusion readied that the gene 

 for cin-ved is liorne iiy a cliroinosonie whicii jiivt's free assortment with IV. 



///. Ilclittrior of riirr((l irilli siiinclrs.s. (liiotnonome III . 



1. ('ur\r<I 9 l)y spineless o"'. 

 Spineless, a mutant cliai-acteri/.ed l)y tlie aitsence of hristles on tlie thorax, 

 was tirst desciiiied hy I'.ridues. Its gene belongs to Chromosome III. All 

 children from the curved 9 hy spineless ^a were characteristic of the wild 

 ty])e. These wIkmi inhred in pairs uave in the V, generation the different 

 classes as shown in tahle 111. 



Table III. F2 generation from curved 9 by spineless cf . 



