354 NEUROPTERA CHAP. 



as to these is chiefly to be found in Grassi's work. The two 

 species studied by him were wingless. They live under stones, 

 where they spin webs by means of the front feet, whose first 

 joint is, as we have said, enlarged and contains glands ; the 

 Insect uses the webs as a means of support in progression, acting 

 on them by means of papillae and a comb-like structure placed 

 on the four posterior feet. 



Grassi informs us that these Insects are not uncommon under 

 stones in Catania ; they require moisture as well as warmth, but 

 not too much ; sometimes there is only one individual found 

 under a stone, at others eight or ten. In the winter and spring 

 their galleries are found on the surface of the earth, but in 

 the hot months of summer they secure the requisite amount 

 of moisture by sinking their galleries to the depth of ten or 

 fifteen centimetres. Their food consists chiefly of vegetable 

 matter. They may be reared with ease in glass vessels. Other 

 species of the family attain wings ; the details of the process are 

 not well known. Oligotoma michaeli (Fig. 222) was discovered 

 in a hothouse in London among some orchid roots brought from 

 India, and was found in more than one stage of development ; 

 the young greatly resemble the adult, except in the absence of 

 wings. A nymph-form is described by M'Lachlaii * as possess- 

 ing wings of intermediate length, and Hagen has suggested that 

 this supposed nymph is really an adult female with short wings. 

 If this latter view be correct, nothing is known as to the mode 

 of development of wings in the family. It is still uncertain 

 whether female Embiidae ever possess wings. Wood-Mason and 

 Grassi have shown that there are wingless females in some species, 

 and we know that there are winged males in others, but what the 

 usual relation of the sexes may be in this respect is quite uncer- 

 'tain. These Insects have been detected in various parts of the 

 world. In the Sandwich Islands Oligotoma insularis was dis- 

 covered by the Rev. T. Blackburn in the wood and thatch form- 

 ing the roofs of natives' houses. A species has been found in 

 Prussian amber, and Grassi thinks that Em~bia solieri one of 

 the Mediterranean species is not to ,be distinguished with cer- 

 tainty from the Insect found in amber. 



Embiidae still remains one of the most enigmatic of the 

 families of Insects. Although Grassi's recent observations are 



1 J. Linn. Soc. Zool. xiii. 1878, pi. xxi. f. 2. 



