126 TRANSACTIONS OF THE [SEsS. LEXY. 
Mires AND ACARODOMATIA. 
By Professor G. F. Scort-Etxior, M.A., B.Sc., F.LS. 
A Swedish botanist, Lundstrom (1), published in 1887— 
now a very long time ago—a classical paper upon mites and 
their dwelling-places, or, as he called them, acarodomatia. 
It was then a new subject, and the article, deservedly, 
attracted a great deal of attention. It is seldom that an 
original research is not only thorough, exhaustive, and 
exactly careful in details, but is also both suggestive and 
extremely interesting. 
Quite a number of other botanists began to observe 
mites and look out for acarodomatia during the next few 
years. Then, however, followed an interval during which 
I have not met with any papers on the subject. Since 
1903, however, several Italian and other botanists have 
been studying mites, and the attention of British botanists 
should be directed to this interesting subject. 
The mites are a well-defined and strictly limited class 
of insects, and yet within the group there is an astonishing 
variety not only in structure but also in habit of life. 
To the mites belong Tetranychus (red spider), Phytoptus 
(the currant mite), and Tyroglyphus, which are amongst 
the very worst vegetable parasites known to us. Certain 
mites are parasites on animals and birds, such as that which 
forms scabies (or itch) in man. Others live on the feathers 
of birds. Some live almost entirely in water, and many 
are saprophytic. Others, again, are active and nimble 
hunters, true carnivorous animals preying upon all sorts of 
minute insects. 
The particular group of which I wish to speak includes 
especially two species, Tydeus foliorwm and Gamasus 
spp. I am not a sufficiently good entomologist to be able 
to say anything about the classification of these mites, and 
I am not sure if these names still hold. What has inter- 
ested me most has been their ways of life and their part in 
the economy of the vegetable world, and it is under these 
names that they are mentioned in botanical literature. 
These particular mites are exceedingly common, as one 
soon realises when beginning a systematic search for them. 
