NEW TYPES OF CHROMOSOME DISTRIBUTION. 143 



described. No direct evidence is at hand, yet I still think 

 there is a possibility that the deeply staining body is a plasmo- 

 some in which are the five differential chromosomes. While 

 reasoning by analogy may not always be a safe method, the 

 above interpretation, it seems to me, is supported by a compari- 

 son of the nucleolus here with those in Fig. i, N (Diplocodus}, 

 and Fig. 4, TV (Conorhinus}. In these two figures the nucleolus 

 stains as intensely black as in Gclastocoris, yet it is evident that 

 the differential chromosomes are present, although invisible. 



Acholla inultispinosa De Geer. 



Montgomery has also described in part the spermatogenesis of 

 a form which he called "Acholla inultispinosa," but according 

 to Van Duzee's identification he was here again mistaken in the 

 species. As previously stated, my figures of the first maturation 

 division, metaphase, in Acholla multispinosa, agree in number 

 and size relations with Montgomery's figures of the same stage 

 in " Sinca." Again his figures of "Acholla inultispinosa" agree 

 with my figures of the first division in Acholla ampliata. So it 

 seems very probable that the species which he called " Sinea 

 diadcuia" is Acholla inultispinosa, and that his "Acholla multi- 

 spinosa " is Acholla ampliata. 



The behavior of the chromosomes in Acholla inultispinosa is, 

 in several respects, more remarkable than in any of the other 

 species examined. The number of chromosomes in the female cells 

 (Fig. 10, A, B and O is 30, six of which are much smaller than 

 the others. The male cells (Fig. 10, D, E and F] show 26 

 chromosomes, one of which is much larger and three much 

 smaller than the remaining ones. At first sight, no evident rela- 

 tion is seen between the male and female groups. A relation 

 becomes evident, however, from a study of the first and second 

 maturation divisions. In the metaphase plate of the first division 

 (Fig. 10, H, I and /) are 16 chromosomes. The three small 

 ones are present and also the large one, which at this time is 

 linked with two other chromosomes, one in contact with each 

 end. This same grouping is present in the prophase of the first 

 division (Fig. 10, G}. Since there are 26 chromosomes in the 



