408 Miscellaneous. 



Among the Thysanura (Campodeae aud Poduridae) the evolution is 

 more accentuated, inasmuch as the Poduridae have still at the base 

 of the antennae some globules of a reddish colour, whilst the 

 Campodeae have no trace whatever of a visual organ. 



Certain sense-organs suppl}^ the place of the eye. Thus the 

 antennae of the Campodeae, which in certain individuals are still 

 almost normal, reach in others a length more than double (the 

 normal) and become longer than the body. The same takes place 

 with the anal fork. The tactile hairs which cover the body take on 

 an exaggerated development, and appear in the Crustacea to go so 

 far as sometimes to invade the eyeball. 



The sense of hearing, on the other hand, does not appear to be 

 proportionately increased, aud a great noise may be made near a 

 subterranean lake without startling the animals (in it). 



The sense of smell seems to be very acute, and putrid food left in 

 the water or on the ground is in a few minutes attacked by a large 

 number of creatures. 



The dif/estive organs are considerably modified, as the result of a 

 mode of life which sometimes extends to the complete absence of 

 animal food in species normally carnivorous. Thus two (specimens 

 of) Sfcqjhylias caught in June last in the grotto of Baurae-les- 

 Messieurs (Jura) bad their mandibles atrophied. 



The dige.-itive tube of the Crustacea is found to be almost always 

 full of clay from the bottom of the lakes, which contains nothing 

 bey 01] d the mineral matter except great quantities of microphytes 

 (algae, moulds, spores, &c.). Under the influence of this regime, 

 the digestive tube appears to have enlarged, sometimes it presents 

 knots and a certain tendency to twisting. 



All the animals are dejncpnented more or less completely. Some 

 specimens still possess, hoAvever, a slight rosy coloration or minute 

 irregular patches of black pigment in contrast with the colourless 

 ground of the tissues. With regard to tliis point, it appeared to me to 

 be of interest to replace certain individuals in the light and observe 

 what would happen. The experiment, interrupted by accident at 

 the end of about a month, was nevertheless even then conclusive; 

 the individuals were carefully taken from amongst the most etio- 

 lated, as exhibiting no trace whatever of pigmentation. In this 

 short space of time, one could watch the appearance of quantities 

 of small black specks, scattered over the whole body, and especially 

 abundant on organs accidentally amputated and in course of repair, 

 such as the antennae and feet. It appears, then, that this pheno- 

 menon occurs fairly rapidly. Later observations on this head will 

 be reported. 



The animals found may be classed as follows : — G species of Crus- 

 tacea (Amphipoda and Isopoda), 2 species of Thysanura, 1 Acarid, 

 2 Arachnids, 1 Gasteropod, &c. They were taken principally 

 from the grottoes of Sainte-Catherine, at Consolation, Commune 

 of Maisonnettes (Doubs), Baume-les-Messicurs (Jura), Les Planches, 

 near Arbois, and Les Nans, near Nozeroy. — Comjites liendus^ 

 t. cxxii. pp. 486-487. 



