GENITAL SYSTEM OF LYCTUS BRUNNEUS. 581 
On the Genital System o£ Lyctus brunneus Steph., with a Note on Lyctus 
linearis Goeze (Coleoptera). By A. M. Altson, F.E.S. (C'om- 
municated by Dr. A. D. Imms, F.L.S.) 
(Plates 31-34, and Text-figs. 1-4.) 
[Read 3rd May, 192.3.] 
Contents. 
Page 
Introduction 581 
Technique and Methods 58ii 
Male Genital System 583 
Female Genital System 586 
Coition , 590 
Note.9 on the Genital System of Lyctus linearis Goeze .... 590 
Observations on Stein's ' Female Reproductive Organs in 
Coleoptera ' 691 
Note on the Morphology of the Apex of the Abdomen in 
Lyctus brunneus Steph 592 
Summary 594 
Acknowledgments , 595 
Bibliography 595 
Explanation of the Plates 696 
Reference Lettering 697 
Introduction. 
In the following description of the genital system of Lyctus brunneus Steph., 
it has been found necessary to add a comparative description of part of the 
alimentary tract of both sexes ; that of the male discloses nothing remark- 
able in the position of these parts, whereas that of the female is curiously 
situated, and appears to be only partially adapted to meet its particular 
method of ovi position. 
Sharp and Muir (10) figure and describe the male genital tube of 
L. linearis Goeze (canalicidatus Fab.). Other than this, no reference to the 
genital system of either sex of any species of Lyctus has been found. 
To complete the examination of the organs of the female L. brunneus, it 
was necessary to cut series of sections. Longitudinal and transverse sections 
were made of pupae, immature and mature adults. " Immature adults " 
refers to beetles removed from their pupal chambers before either their 
integument had hardened or they had eaten any wood, i. e. between i'our 
and five days after shedding the pupal exuvise. 
Tlie beetles are not sexually mature until they are ready to emero-e ; 
mating invariably takes place at the earliest possible opportunity after that 
event. 
linn. JOURN. ZOOLOGY, VOL. XXXV. 43 
