The Zoologist — June, 1866. 239 



extremity with two hooks and two longitudinal and parallel rows of 

 delicate tenent hairs; by the aid of these this Acarus walks with some 

 liltle hesitation in an inverted position upon gla§s. 



The anus I believe to be represented by two slightly projecting 

 flaps at the free extremity of the abdomen, immediately below which 

 is a longer aperture, from which I presume the egg is emitted. 



Wherever this Acarus in a natural state deposits its eggs, in that part 

 it takes up its quarters and remains for a considerable time : this is in 

 fact necessary for the protection of its eggs, which would otherwise be 

 devoured by Acari of the same and probably other species. They will 

 frequently destroy their own eggs themselves when disturbed, or when 

 pressed for food. 



Having these Acari now well established in a cupboard I mostly find 

 them partially concealed in some small cavity, and when in a mature 

 state standing over a quantity of eggs in every stage of development ; 

 the empty egg-shells from their extreme thinness reflecting a brilliant 

 blue light, which catches the eye more quickly than the Acarus 

 itself. 



My object from the first in securing this Acarus, and in keeping it 

 alive was to obtain specimens of both sexes, but I have never yet been 

 able to detect a male. I was much surprised to find that every speci- 

 men I selected laid eggs, all of which duly hatched, and to make sure 

 whether this was really a case of agamic reproduction, I determined to 

 isolate some individuals very carefully, and I obtained the following 

 results. In all these experiments I have employed the " live traps " 

 which I described in the last number of the 'MicroscopicalJournal of 

 Science,' and they have answered perfectly, not only in completely 

 isolating the specimens, but also enabling me to put them under the 

 microscope, or to supply them with food at any time without disturbing 

 them in the least. 



On July 10th, of this year, a young Acarus of this species was taken 

 from a trap in which there was only a mature female ; it was com- 

 pletely isolated, and on the 29th of the same month it laid eggs, which 

 hatched on the 4lh of August. One of these on the day it was hatched 

 was removed to a trap and also completely isolated; by the I3th of 

 September it had laid eggs, and some had hatched. On the 19lh of 

 September two of the young from the last mentioned trap w'ere 

 separated and secured : these I now have living and in a mature state ; 

 neither have as yet laid eggs, but I fully expect they will do so unless 

 the approach of colder weather retard the process of reproduction, 



