CHROMOSOMES IN THE SPERMATOGENESIS OF THE HEMIPTERA HETEROPTERA. 



153 



very nearly complete. Data on hybrids are omitted ; and data from certain older 

 papers, as that of Carnoy (1885), where no particular pains were given to deter- 

 mining the numbers accurately, are left out. In the first vertical column of each 

 table is given the name of the group, subgroup and species ; in the second column the 

 germinal cycle is indicated by the abbreviation " Ov " for ovogenesis, and " Sp " for 

 spermatogenesis, in the third column are the names of the describers ; and in the 

 remaining columns the headings " Gonium," " Cyte 1," " Cyte 11," and " Tid " stand 

 respectively for ovogonium (or spermatogonium), first ovocyte (or spermatocyte), 

 second ovocyte (or spermatocyte), and ovotid (or spermatid). In these tables allosomes 

 are not distinguished from autosomes since the intention is to present the entire 

 chromosomal numbers. When a number is given as, e. g., " 10-11 " it means that it 

 was not determined whether 10 or 11 is present; but when it is stated "10, 11," it 

 signifies that either 10 or 11 may be present, which of course would be a cycle com- 

 plicated by the presence of a monosome. For the Hemiptera when my name is given 

 as an authority, reference is made to the observations of the present paper. 



Group and Species. 



Vertebrata. 



1. Mammalia. 



Bos taurus 



Lepus cuniculus. 



Miis rattus 



Musrattus 



Cavia cobaya 



2. Aves. 

 Columba livia. ... 



, Amphibia. 



Triton alpestris ~) 



Triton cristatus ^ 



Triton punctatus ) 



Salamaudra maculosa... 

 Batracboseps attenuatus 

 Desmognathus fusca. ... 



Plethodon cinereus 



Diemyctilus torosus 



Amphiuma means 



Bufo lentiginosus 



Rana temporaria 



. Pisces. 



Myxine glutinosa 



Salmo fario 



Scyllium canicula 



Pristiurus 



Torpedo | 



Raja J 



Cycle. 



Sp. 

 Ov. 



Sp. 



Ov. 



Sp. 



Ov. 



Sp. 

 Ov. 



Sp. 

 Ov. 



Sp. 



Authority. 



ScbocDfeld, IflOl. 

 Winiwarter, 1900. 

 Lenbossek, 1S98. 

 Moore, 1894. 

 " 1906. 



Harper, 1904. 



Janssens, 1901. 



Meves, 1896; Janssens, 1901. 

 Eisen, 1900; Janssens, 1903. 

 Kingsbury, 1902; Montg. 

 Montg., 1904; Janssens, 1903. 

 Lebrun, 19016. 

 McGregor, 1899. 

 King, 1901, 1905. 

 Lebrun, 1901a. 



Schreiner, 1905. 

 Bohm, 1892. 



Moore, 1895. 



Cyte II 



12 



8 



16 



12 



12 

 12 

 12 

 12 

 12 

 12 

 12 

 10 



26 

 12 



12 



Tid. 



12 

 16 



12 



12 

 12 



12 

 12 

 12 

 12 

 12 



26 



12 



12 



A. P. S.— XXI. Q. 27, 8, '06. 



