EGG-CASE OF THE COCKROACH. 239 



That of the domestic species is wonderfully large considering 

 the size of the insect, being three-eighths of an inch in length, 

 and nearly half as much in width. It is shaped something like 

 an oblong steel purse, the part which represents the purse itself 

 Ving well rounded, and that which represents the clasp having 

 a row of very fine notches. When the young are hatched, they 

 escape through this portion of the egg-case, the whole side 

 opening exactly like the clasp of a purse, and, owing to the 

 plasticity of the material of which the case is composed, the 

 opening closes as soon as the young have escaped, and ex- 

 ternally the egg-case looks exactly as it did when the eggs 

 were still in it. 



If the empty case be cut open a curious sight presents 

 itself. On the outside of the case are eight small rounded 

 projections, set in a row just beneath the opening. When the 

 interior of the case is shown, a double row of eight cells is seen 

 to occupy it, half of the cells lying on either side of the case ; 

 each cell being lined with a stout yellowish membrane, and 

 the end of the cells exactly corresponding with the little projec- 

 tions which have just been mentioned. The mother Cockroach 

 takes a considerable time in depositing this egg-sac, and carries 

 it about with her for several days before she finally places it 

 in the spot where the young are to be hatched. 



Another species of Cockroach is shown on Plate VII., 

 Fig. 3. This is the Field Cockroach {Blatta germanica), a 

 much smaller insect than the domestic species. 



Its colour is a pale yellow, sometimes taking a reddish hue, 

 and on the large prothorax are two conspicuous longitudinal 

 black lines, a peculiarity by which it may at once be recognised. 

 Unlike the domestic Cockroach, which only lives in houses, the 

 Field Cockroach lives in the open air as well as in houses, and 

 in the former case is to be found under decaying leaves and 

 similar situations. There is a slight difference in the colour 

 of the insect, according to its habitation, the paler specimens 

 being those of the open air, and the reddish hue belonging to 

 those which live within doors. 



Whether or not this species is indigenous is a mooted point, 

 but in all probability the insect has been introduced from the 

 Continent. Mr. Westwood remarks that he has received it 



