136 Origin of the Araneidal Fauna of Yorkshire. 
indigenous than the others, yet on the other hand it may have 
been there long enough to permit of its increase and dispersal 
in favourable surroundings in what is after all a limited area. 
When the products are transported over greater or shorter 
distances by land the same transference of spiders or their eggs 
probably also happens, but owing to their highly developed 
instinct of concealment, their small size and the lack of inter- 
ested and intelligent observers, the event passes unnoticed. 
In this connection trees transplanted from one part of the coun- 
try to another for the purposes of afforestation constitute a 
likely medium for the introduction of new species into the latter. 
Dr. Jackson, in his ‘ Spiders of the Tyne Valley,’ p. 602, 
expresses an opinion that the south British species, Tegenaria 
atrica C. L. Koch. was certainly introduced’ by man into the 
Botanic gardens, Southport, whence it has spread into other 
parts of the surrounding district. An adult female of the same 
species recently (Nov. rg1r) travelled unharmed in a crack of 
a poplar tree from Montgomeryshire to a Huddersfield timber 
yard. An instance of a similar character is given by Dr. de 
Lessert in his “ Notes sur la Repartition Geographique des 
Araignées en Suisse’ (1909), p. 487, the introduction into a 
Swiss tannery of Tegenaria parietina Fourcroy, along with 
oak bark received from the South of France. Occasionally 
spiders are carried into more unusual places, but generally 
the manner of their conveyance there is self-evident. Porr- 
homma microphthalmum Camb. has been met with in some 
quantity down a coal mine in county Durham, the vehicle in 
this case being fodder for the ponies. A dry barn in the Colne 
Valley has yielded several examples of typical hygrophiles. 
Antistea elegans C. L. Koch., Hilaiva excisa Camb. and Lo- 
phomma punctatum Bl., all housed with hay from wet fields 
during previous years. At Redcar, in August, 1909, Tapinocyba 
subitanea Camb., usually a cellar and stable dweller, was noted 
in abundance on the coast close to the spot where the rubbish 
from the tradesmen’s cellars is carted to be burnt. 
Man’s activities in other directions, however, are as a rule 
exercised at the expense of the lower creation, their favourite 
haunts being sacrificed to the needs of his improvements. 
The practice whichis prevalent every spring in many parts of 
S. W. Yorks of setting fire to the vegetation of long stretches of 
rough land in high pastures and on moors (‘ tatching’ as it is 
called), together with the accidental or intentional firing of 
the heather must annually cause great destruction of small 
creatures. and their eggs. So also must the construction of 
large reservoirs and the bringing of land under cultivation, 
either by clearing away woodland, draining fens, mosses, etc.., 
or by reclaiming waste and moorland—as much by re- 
stricting the area wherein they can thrive, as by the actual 
Naturalist, 
