THE ANNALS 



AND 



MAGAZINE OF NATURAL HISTORY. 



[SIXTH SERIES.] 

 No. 27. MARCH 1890. 



XX VII. — On Abdominal Appendages in Hexapoda. 

 By E. Haase*. 



In his celebrated memoir upon the development of the Great 

 Water-Beetle (Hi/dropki/us piceus) A. Kowalewsky, in 1871, 

 first called attention to the fact that in the embryo of an 

 insect stages might occur in which certain abdominal seg- 

 ments bear appendicular structures homologous with the 

 thoracic legs. He first observed such leg-rudiments on the 

 first two abdominal segments, and then saw the posterior pair 

 disappear, while the anterior remained longer in the form of 

 small tubercles. These results of Kowalewsky's were exten- 

 ded by K. Heider in 1886 f so far that " at a certain period 

 of development indications of the rudiments of extremities 

 may be recognized on all the abdominal segments." 



In 1877 V. Graber J succeeded in establishing the occur- 

 rence of rudimentary appendages homologous with the legs 

 on the first and second abdominal segments in a Mantis [M. 

 religiosa) . 



In 1884 H. Ayers found that in an American Cricket 



* Translated from the ' Sitzungsberichte der Gesellschaft Naturfor- 

 Bchender Freunde zu Berlin/ Jahrg. 1889, pp. 19-29. 



t Abhandl. d. k. preuss. Akad. d. Wiss. in Berlin, p. 42. 



X ' Die Insecten,' i. fig. 1 ; and see Morphol. Jahrb. xiii. (1888), tab. 

 xxv. fig. 18. 



Ann.& Mag. N. Hist. Ser. 6. Vol. v. 16 



