NO. 2 ENCYCLOPEDIA OF INSECT ANATOMY — SNODGRASS 45 



parative study of the ovipositor muscles, however, Matsuda concludes 

 that the musculature does not support the idea that the ovipositor 

 has been derived from a pair of abdominal limbs. He concludes that 

 the valvifers are sternal in origin, as claimed by Heymons. Certainly 

 the ontogenetic origin of the ovipositor in the larva does not suggest 

 that its rudiments represent legs. In the higher insects, as the 

 writer (1933) has shown in the honey bee, the ovipositor is de- 

 veloped from two slender median processes on the venter of the 

 eighth abdominal segment and two pairs on the ninth. These 

 processes no more suggest a homology with legs than do the rudi- 

 ments of the male genitalia. 



Hence, if we do not wish to discard the idea of the leg origin of 

 the ovipositor, the subject must remain doubtful until substantiated 

 by better evidence than is at present available. The ovipositor is an 

 organ peculiar to the insects that possess it. In no other arthropod 

 is there any such stnjcture, either anatomical or functional, associated 

 with the opening of the oviduct. 



Morphological generalizations are mental products of morphol- 

 ogists, but they are always intriguing in that they bring a lot of 

 seemingly unrelated facts into a single concept. In this way they may 

 be more convincing by the mental peace and satisfaction they give 

 than by the evidence from the facts on which they are based. We must 

 be cautious, then, not to accept a generalization on its mental appeal 

 alone. 



LITERATURE CITED 



BoRRADAiLE, L. A., and Potts, F. A. 



1958. The Invertebrata, ed. 3 (edited by G. A. Kerkut), 795 pp. Cam- 

 bridge University Press. 

 DuPORTE, E. M. 



1960. Gastrulation and tlie endoderm problem in insects. Ann. Ent. Soc. 



Quebec, vol. 6, pp. 45-52. 

 1962. Origin of the gula insects. Can. Jonrn. Zool., vol. 40, pp. 381-384. 

 Garstang, W. 



1922. Tlie theory of recapitulation: A critical restatement of the biogenetic 

 law. Journ. Linn. Soc. London, Zool., vol. 35, pp. 81-101. 

 Henson, H. 



1946. The theoretical aspect of insect metamorphosis. Biol. Rev., vol. 21, 

 pp. 1-14. 

 Heymons, R. 



1899. Der morphologische Bau der Insektenabdomens. Eine kritisehe 

 Zussamenstellung der wesentlichen Forschungsergebnisse auf ana- 

 tomischen und enibryologischen Gebiete. Zool. Centralb., vol. 6, 

 pp. 537-556. 



