SG [^^P'". 



question have for tbeir function the secretion of a particular form of 

 pulverulent wax, and that they are in some vi'ay connected with the 

 process of oviposition. My theory is strengthened by the additional 

 facts that the '' grouped wax-glands " — as I propose to call them — are 

 not found in the male insect, nor in immature females. If their 

 function were digestive, as supposed by Mr. Morgan, one would expect 

 to find these organs well developed in the earlier stages of the insect 

 when assimilation of food is most active. What their exact use may 

 be, or why they should be present in some species and wanting in 

 others, are questions difficult to decide. Can the pulverulent matter 

 serve the purpose of dusting the eggs and preventing their adherence' 

 to each other ? A coating of fine powder would also protect the 

 eggs from injury in wet weather. Certain it is that the eggs of all 

 Coccids are covered with waxy particles similar to those secreted by the 

 grouped glands. 



It is a significant fact that, as far as I have at present observed 

 (dealing with Ceylouese forms only), those species of DiaspincB that 

 have no f/roitped glands are ovoviviparous, tvhilst those in which the wax-- 

 glands occur are strictly oviparous. Of fourteen species of Aspidiotus< 

 I find that nine are possessed of grouped wax-glands and lay eggs, , 

 while five species are glandless and produce living young. I have 

 four species of Aonidia — all without the glands— and in all the embryo 

 is fully developed before extrusion. The species of Mytilaspis occur- 

 ring in Ceylon are amply provided with grouped glands, and deposit : 

 large numbers of eggs. In Biaspis the same conditions occur. In 

 Fiorinia three oviparous species are provided with glands, and one 

 ovoviviparous insect is without them. The same rule holds good in 

 Chionaspis, with the doubtful exception of Gh. hiclavis, Comst. It 

 would help to elucidate the question if other Entomologists interested 

 in this group of insects would record the result of observations of a 

 similar nature. 



In vindication of the proposed term " wax-glands," I would point 

 out that in most of those forms that produce wax of a powdery nature 

 on other parts, glandular pores of very similar structure are freely 

 scattered over the surface of the body, and are more especially crowded 

 on those parts that carry an accumulation of the secretion in the form 

 of loose waxy processes— such as the Dactylopiini and some Mono- 

 phlebince. 



Bearsted, Kent : 



February 17 (h, 1896. 



