50 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 68 



Porta (1903) says that the discharge of the secretion from 

 Coccinella, Timarcha, and Meloe is caused by a reflex phenomenon 

 brought about by any excitement. The Hquid is secreted by a 

 glandular follicle in the reticulum of connective tissue, which is 

 situated in the wall of the middle intestine. The liquid has an acid 

 reaction, and it is perhaps only a bile secretion. He gives three 

 reasons why this liquid is not blood : ( i ) It is inadmissible that 

 insects should constantly pass such an important fluid; (2) after a 

 prolonged excitation the liquid ceases to exude; and (3) it has an 

 acid reaction while we know that blood in all animals has an alkaline 

 reaction. He fails to explain how this secretion reaches the exterior 

 from where it is produced. 



Berlese (1909) seems to think that the discharged liquid from 

 Meloe is a mixture of blood and a secretion from hypodermal glands. 

 In a diagram showing the anatomy of the leg at the femoro-tibial 

 articulation, he figures a receptacle for containing the blood and 

 shows how the blood is ejected through an aperture at this place 

 in the leg. He also shows unicellular glands lying just beneath the 

 hypodermis on both sides of the articulation. Each gland cell is 

 almost spherical, has a conspicuous nucleus and a central vesicle, the 

 ampulla, from which runs the efferent tube through the hypodermis 

 and chitin to the exterior. 



Schon (1911) found unicellular glands beneath the femoro-tibial 

 articulations of Camponotus and the tibio-tarsal articulations of 

 Formica. 



The present writer (1916b) has examined the femoro-tibial articu- 

 lations of the meloid beetles, Cysteodemus armatus and Epicauta 

 pennsylvanica, and of the coccinellid beetle, Epilachna horealis. No 

 slits nor openings, except gland pores, were seen in the femoro-tibial 

 articulations of these beetles. As already mentioned on page 39, 

 hypodermal gland pores are widely distributed over the integument 

 of Epilachna borealis. Usually one, but sometimes two pores, lie 

 near the base of almost every hair. Besides lying near the bases of the 

 hairs, the pores on the tarsi and around the femoro-tibial articu- 

 lations lie in groups. Two groups are located at the extreme proximal 

 end of the tibia and two at the distal end of the femur around the 

 articular membrane. All four groups contain 100 pores as an 

 average. The articular membrane contains about 400 pores of 

 another type. 



These beetles always appear wet, and the more they are irritated 

 the wetter they become. The wet appearance is caused by a hypo- 



