BRITISH HARVEST-SPIDERS
185
I suggest that microscopical examination of the internal organs,
particularly the alimentary canal, would reveal other parasites.
I have records of ten species of harvest-spiders being used as
carriers by the larvae of the red mite Erythraeus phalangiodes
(Degeer), and four of the false-scorpion Lamprochernes nodosus
(Schr.) using four species for the same purpose.
Food : evidence points to harvest-spiders being primarily
carnivorous and feeding either on fresh or dead, but not putrid,
animal tissues. Dr. Bristowe (ibid.) mentions that they will
occasionally browse the gills of chanterelle fungi. Other foods
which he mentions are—living snails, worms, millipedes, woodlice,
spiders, leaf-hoppers, earwigs, flies and fly larvae, an ant, a mite,
a lepidopterous larva, an aphid and bird droppings. My own
records (ibid. 1949a) include an enchytraeid worm, a centipede,
millipedes, insects (Collembola, Hemiptera, Lepidoptera, Hy-
menoptera and Diptera), spiders and mites. In addition I have
noted eight species at the entomologist's sugar patch and five at
the bodies of dead animals.
Life-history: no courtship has been recorded in harvest-
spiders. Mating probably always takes place after dark as this
is the time when most species are active.
The reproductive organs, so different from those of true
spiders, are of taxonomic value as shown in two recent papers
(Sankey, 1949; and Brown and Sankey, 1950). The detailed
structure and functioning of these organs has been dealt with in
the useful papers of de Graaf (1882) and Blanc (1881); I can
make no further mention of them here beyond that these organs
make excellent material for microscope slide mounts (Plate 14
(c, d)).
Two recent papers by Mons. Gueutal of France (1944, 1944a)
increase our knowledge of oviposition and hatching of the egg in
harvest-spiders, and some of my own observations confirm and
add to his work.
The eggs are usually laid in batches in cracks in the ground,
under stones or in other suitable places. The eggs of those
fifteen species which I have seen are whitish and round and
devoid of sculpturing. They adhere loosely together but are
readily separable with a brush. The average weight of the egg of
our largest species, Odiellus spinosus (Bosc) is 0.00046 gram.
Sometimes the eggs of the same batch vary in size. According
to Mons. Gueutal (1944) Phalangium opilio L. lays between 400
and 600 eggs. I have observed O. spinosus to lay 201.
A faint mottling indicates the onset of development. The
eyes appear at one pole of the egg. Just before hatching the
body segments and limbs can also all be seen neatly tucked away
inside the egg membranes (Plate 14 (b)).