356 THE GROUSE IN HEALTH AND IN DISEASE 



given in Snodgrass's already mentioned paper, and Gross 1 has written an account 

 of the histology of the ovary, which he finds strikingly like that of the 

 Pediculidse. 



The eggs are very beautiful objects; in badly-infested Grouse they may be 



numerous, but as a rule they were none too easy to find. Usually they occur in 



small groups attached to the base of the after-plume and between it and the 



shaft of the plume. The specimen figured was on one of the feathers 



from the flank (PI. LIII., Fig. 3). 



The eggs are elongated, some three to four times as long as they are broad. 

 They are fixed by some adhesive secretion at the end corresponding to the posterior 

 end of the contained embryo. At the other end is a well-marked cap or operculum, 

 which always points to the free end of the feather. The beauty of the reticulated 

 egg-case is shown best in the genus Menopon, and we figure one, which we take to 

 be the egg of Menopon pallescens Nitzsch, found on the feathers of a partridge 

 (PL LIII., Fig. 4). Under the pressure of a cover-slip the egg-case gradually ruptured 

 along a circular line below the well-marked thickened edge or rim of the operculum. 

 The contained egg then began to emerge, carrying the operculum as a sort of cap, 

 the resemblance to which was emphasised by the long process which stands out like 

 a feather borne on the apex. The eggs of Goniodes show the reticulations less well, 

 but they are well marked on the operculum, which bears a long tapering filament, 

 longer than the egg itself. They also occur just below the opercular rim, but fade 

 away towards the fixed end. The general appearance of the eggs in the after- 

 plume is shown in PL LIII., Fig. 3. They were found on July 27th, 1908, and 

 they seem to be laid throughout the summer. 



There is no metamorphosis, the young leaving the egg-shell as a miniature of 

 their parents. 



II. NlRMUS CAMERATUS Nitzsch. 



This insect seems to have been first named by Nitzsch 2 in the year 1818, but 

 with no description. Indeed, the animal is mentioned under the subgenus Nirmus, 

 but is called Philopterus cameratus. It is figured and described, and a bibliography 

 is given, in Denny's " Monographia Anoplurorum Britanniae," 3 under the name of 

 Nirmus cameratus. Denny found it on the Red Grouse, the Black Grouse, " and 

 I expect also on the Ptarmigan." Grube describes it in Middendorff's "Siberian 



1 " Zoologische JahrMcher, Anatomie," xxii. p. 347, 1905. 



2 Germar's " Magazin der Entornologie," iii. p. 291. Halle, 1818. 



3 London, 1842, p. 112. 



