234 Transactions of the Society. 



strange organism a nymph or a perfect form ? As before stated, the 

 nymphs are usually soft and light-coloured, the perfect form hard 

 and dark, but this is modified by the fact that with each change of 

 skin the nymph becomes somewhat harder and darker, so that the 

 nymph of a species, the adult of which is very black and hard, as in 

 the legeocrani, becomes, before the final change, as dark and hard 

 as some other species, e. g. many of the genera Nothrus and 

 Eremseus, are after it. To decide this I searched and at last obtained 

 several more living specimens of various ages ; some appeared to 

 show eggs, which strongly favoured the idea that it was an adult, 

 as the appearance somewhat indicated. 1 also obtained ^some cast 

 skins. WhUe in doubt, I received a letter from ]\Ir. George, with a 

 rough sketch of something he had found, which was manifestly my 

 creature ; he had only one specimen, and, like myself, was in doubt 

 whether it was a nymph or adult ; his individual showed eggs, which 

 pointed to the adult theory. I kept all I could get alive for some 

 weeks without any indication of a more perfect stage ; still I could 

 not rid myself of the idea that it was only a nymph, my reasons 

 being, first, that it bore on its back the dorsal parts of the larval 

 and two pupal skins only, and in Nothrus fhelejyroetus and others 

 that I had watched, the nymph had cast its skin twice before the 

 change to the perfect form ; secondly, that I found what seemed 

 to be a discarded skin as perfect as the animal I had alive; if it 

 were, something must have come out of it ; thirdly, I had one dead 

 specimen which seemed to show something forming below the skin. 

 I kept my breeding cages going until the last day of my stay in 

 Epping Forest, without success ; but the evening before I left, one 

 became much darker, and the morning I was leaving for the 

 Highlands the skin of the nymph split, and Tegeocranus lotus 

 emerged as before described. 



I relate this to show the necessity for caution in judging whether 

 a newly found mite is a nymph or perfect creature, and how excu- 

 sable it was in Koch to figure them often as separate species, writing 

 when he did. 



I have mentioned above that some specimens apparently contain 

 eggs ; it is quite possible that Mr. George and I were mistaken, and 

 that they were not eggs ; their being so seems inconsistent with the 

 dissolution and reformation of the animal in the change from nymph 

 to imago ; but it must be remembered that 0. Kobin has shown * 

 that the male Dermaleichi copulate, not with the final form of female, 

 but with an intermediate form, which in appearance almost exactly 

 resembles the nymph ; and the same author and Megnin have de- 

 monstrated that this intermediate form, which they call " femelle 

 accoujyJee,'' often shows eggs, although not provided with any vulva 

 of gestation, which only appears in the final form of female. This 

 * ' Comptcs Keiidus,' 1868, p. 776. 



