36 THE entomologist's UECORD. 



be thus resting, whilst one looked straight at it without discovering it, 

 so perfectly was it protected. He had repeatedly found them sitting 

 thus, but only after much close searching, and he had often been 

 struck by the marvellous way in which they were protected. It was 

 further remarkable that at Forres, both dark and light forms of T. 

 orbona occurred, but whilst there was some little intermingling, as 

 might be expected, in contiguous areas, yet, it was remarkal)le how 

 large a proportion of the dark specimens was strictly confined to the 

 low-lying peaty ground, whilst on the drier and higher land, and in the 

 woods around, the ordinary grey forms, such as were found in the 

 Southern counties, occurred almost entirely. On the sand-hills, 

 at a very short distance, only the most ordinary grey forms were 

 to be obtained, the dark forms scarcely appearing, even as a rare 

 aberration, although one might reasonably expect that specimens of a 

 strong-winged species like this would cover a large area easily enough 

 when on the wing. 



In Orkney, only melanic specimens of T. orhona are found ; no 

 grey ones have ever been taken. Here they occur entirely on peaty 

 land, and the pale form has become entirely eliminated. In the 

 Island of Lewis, again, pale and dark forms were found, the conditions 

 of environment being, however, dift'erent for the dili'erent forms. 



Such evidence as this is of the highest value, and it is to be 

 regretted that Messrs. McArthur, Rcid and Salvage are so chary of 

 recording their observations. There can be no doubt, as we are 

 attempting to show in our papers on " Mimicry," that the same 

 general laws hold good all round. (1) The germ contains endless 

 variational units. (2). These compete amongst e^ich other by intra- 

 selection. (3) Forces (nutrition, moisture, temperature, etc., etc.) 

 acting on the organism determine which variational units shall be 

 most successful. (4) Selection chooses those variations that will be 

 most useful for the protection of the organism, and directs them into 

 lines that will serve best to protect it. 



It may be asked, what influence we think the excessive moisture of 

 some of the areas, where these forms occur, has in moulding the 

 melanism of this species. The influence it certainly has is to intensify 

 the blackness of the peat and heath, and hence to aid in intensifying the 

 blackness of the species, the specimens of which respond, under the 

 above conditions, to the environment. It may also be a factor that 

 gives certain variational units (Weismann) an advantage, and aids 

 them in their struggle against other units, Lc., it may be a factor in 

 the process of intraselection. 



.SCIENTIFIC NOTES AND OBSERVATIONS. 



An unusual pairing of T.eniocampid species. — I have been ex- 

 tremely busy of late, working sallows near here, and have done 

 extremely well. I took a male Taeninraiii/ia stabilis in copula with 

 a female 7'. nnonla. The latter laid about 160 eggs, which have 

 changed colour, and will, I believe, prove fertile.— W. HEvvKxr, 12, 

 Howard Street, York. A]>ril llth, 1H96. 



The genera in the Apatelid.e. — Now that Dr. Chapman has given 

 us his authority that " not only are Cuspidia, Viniinia and liisnlcia 

 good genera, but that Cmpidia must be sub-divided into genera, much 



