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Sidnej’ I. Kornhauser 
chromososomes as are found in E. binotata and E. curvata may also 
be found in the homopterous Hemiptera. 
XI. Summary. 
1. In Enchenopa bimtata and E. curvata the large apical cell at the 
distal end of each tubule of the testis functions in the nutrition of the 
spermatogonia. Its long cytoplasmic processes are larger and more 
distinct when degenerating cysts are present. 
2. The sperniatogonial number of chromosomes in E. binotata is 
twenty; two macrochromosomes, and eighteen smaUer chromosomes. 
3. The spermatogonia! number of chromosomes in E. curvata is 
nineteen; two macrochromosomes and seventeen smaUer chromosomes. 
4. The oögonial number of chromosomes in both species is twenty; 
two macrochromosomes and eighteen smaUer chromosomes. 
5. The double threads of the bouquet stage are formed by the side- 
by-side union of the leptotene threads in pairs (parasymdesis) in both 
species. Syndesis takes place before a regulär polar arrangenient of the 
loops is assumed. In both E. binotata and E. curvata there are nine double 
loops equivalent to eighteen autosomes of the spermatogonia. One loop 
is much longer than any of the others and doubtless corresponds to the 
macrochromosomes. 
6. In E. bimtata a pair of deeply staining threads come together 
end to end in the early bouquet stage and afterwards become approximated 
side by side. One is a solid rod, the other is granulär and contains less 
chromatin. This pair of threads forms a geniinus (xy) in the early pro- 
phase of the first spermatocyte before the autosomes have fuUy contracted. 
It is characterized by its deep stainability, by a single thick Strand con- 
necting the two components, and by the absence of a longitudinal line 
of division. This pair of aUosomes (xy) bears characteristics of both 
heterochromosomes and autosomes. 
7. In E. curvata there is a single a:-chi-oniosome, deeply stainable 
throughout the growth of the sperniatocytes, and in Connection with it 
are several chromatic nucleoli. These nucleoli offen retain their Con- 
nection with the a^chroniosome and also become attached to the auto- 
somes. They gradually disappear in the late strepsistene stage leaving 
the deeply stained a:-chromosome connected to the autosomes by distinct 
hniii fibers. 
8. In the metaphase of the first spermatocyte of E. bimtata there 
are ten bivalent chromosomes: viz. one macrochromosome geminus, eight 
