January 5, 1906.] 



SCIENCE. 



37 



an attitude that would appear ungenerous and 

 might even arouse some hostility, yet at the 

 same time I relinquish previous names of my 

 own that have been employed in various 

 papers and have been adopted to some extent 

 by others. Indeed, it would have been just 

 as satisfactory to me had these emendations 

 proceeded from some other worker. 



In the second place a preliminary report 

 upon reinvestigations of the spermatogenesis 

 of two families of the Hemiptera heteroptera 

 will be given in brief. 



In the Pentatomidse there is one pair of 

 diplosomes in the spermatogonia, which al- 

 ways conjugate to form a bivalent one in the 

 early growth period; these relations are ex- 

 actly as I previously described them. Tricho- 

 pepla only appears to possess an additional 

 pair of very minute components. But I had 

 formerly concluded that such a bivalent diplo- 

 some in this family always divides reduction- 

 ally in the first maturation mitosis, so that its 

 two components would be carried to different 

 daughter cells (second spermatocytes). Wil- 

 son has recently shown, however, that in this 

 first mitosis the two diplosomes lie separately 

 in the equatorial plate, and that each divides 

 there equationally; and he finds that in each 

 daughter cell (second spermatocyte) the two 

 daughter diplosomes conjugate in the equa- 

 torial plate and are there separated by a re- 

 duction division. Wilson is quite correct with 

 regard to this phenomenon, and I had failed 

 to notice (except in Euschistus tristigmus) 

 that in the later growth period of the first 

 spermatocytes there takes place a separation 

 of the components of the first bivalent diplo- 

 some. Further, I have recently found that 

 in all the genera reexamined each diplosome 

 becomes longitudinally split during the growth 

 period. As to the number of autosomes in 

 the spermatogonia of the Pentatomidae : in 

 Euschistus variolarius there are usually 

 twelve, but in two cells there are at least 

 thirteen, and possibly fourteen; the meaning 

 of these differences I have not yet determined. 

 There are also twelve autosomes in Euschistus 

 tristigmus, Nezara hilaris, Perillus confluens, 

 Ccenus delius and Trichopepla semivittata. 

 There are fourteen in Podisu^ spinosus and 



Cosmopepla carnifex; my preparations of 

 Peribalus limholaris have faded to such an 

 extent that I was not able to restudy this 

 form. 



In the Coreidse I had previously described 

 the occurrence of monosomes only for Har- 

 mostes, Protenor, Alydus eurinus, and sug- 

 gested the possibility of the presence of a 

 monosome in Chariesterus. Wilson has re- 

 cently shown that there is a monosome also in 

 Anasa, contrary to the earlier descriptions of 

 Paulmier and myself. Eeexamination of my 

 preparations demonstrates that in all the 

 CoreidsB studied there occurs a monosome in 

 the spermatogenesis. It is the odd chromo- 

 some of the spermatogonia, always divides 

 in the mitoses of these cells, divides also in 

 the first maturation division, but in the second 

 maturation division passes undivided into one 

 of the daughter cells (spermatids). In all the 

 genera studied this monosome retains its com- 

 pact form during the growth period of the 

 spermatocytes. Further, in each species studied 

 of the Coreidae there is a single pair of diplo- 

 somes in the spermatogonia, these regularly 

 conjugate in the growth period, and divide 

 reductionally in the first maturation division, 

 as previously described by me. To these ob- 

 servations I can now add that each diplosome 

 becomes longitudinally split in the growth 

 period, and that each divides equationally in 

 the second maturation division; and that they 

 remain compact during the growth period in 

 Anasa, Gorizus, Harmostes, Protenor and 

 Chariesterus, but not in Alydus and Meta- 

 podius. The number of chromosomes in the 

 species investigated is as follows: Anasa 

 tristis, A. armigera, A. sp. (from California), 

 Metapodius terminalis : eighteen autosomes, 

 one monosome, two diplosomes; in Alydus 

 pilosulus, A. eurinus, Corizus alternatus, Har- 

 mostes reflexulus and Protenor helfragei: ten 

 autosomes, one monosome, two diplosomes; no 

 clear views of spermatogonic monasters of 

 Chariesterus antennator were found, but judg- 

 ing from the relations in the spermatocytes 

 there are in the spermatogonium probably: 

 twenty-four autosomes, one monosome and two 

 diplosomes. 



The main errors in my preceding work 



