Smithsonian Report. 1935. — Morgan 



The chromosomes of the sahvary gland of the female larva of Drosophita 7ittianogasti:T[(eiUeT Painter), 

 The two X-ehromosomes are fused into a single body. This chromosome is attached at one end to the 

 common chromocenter at its attachment end. The second and third chromosomes have the attachment 

 point near the middle and are fused with the common chromocenter at this point, leaving two free ends 

 of each chromosome. Like limbs of each of these free ends are fused, giving four free ends in all. 



. The relative sizes of the chromosomes in the calls of the gonad (a), of the giant ganglion cells' of the 

 bram (d), and of the prophase stage of the latter (b, c). In (a) ametaphase plate from the gonad is shown. 

 In (6) a prophas3 stage from a ganglion cell showing the black (heavily stained) inert regions of the 

 chromosomes and the faintly stained regions carrying most of the genes, according to Heitz. In (c) the 

 late prophase of the same type of cell is shown intermediate between (6) and (d). The genetic region is 

 now stained. In (d) (male) the metaphase of a ganglion cell has chromosomes larger than those of the 

 gonad cells as shown in (a). 



