SCIENTIFIC SUMMARY. 
373 
strong-smelling substances, by moving their antennae and turning sharply 
round. But when their antennae had been previously removed, the same 
insects gave no signs of perception, even when they were placed quite 
close to the turpentine or acetic acid. Flesh flies, from which the third 
joint of the antennae had been cut away, were no longer attracted by the 
putrid meat, for which they had previously shown great fondness ; they flew 
about as before, but no longer scented the meat from a little distance; 
Enveloping the antennae with a thin coating of paraffin produced the same 
effect. 
M. Hauser made an anatomical investigation of the antennae, and camo 
to the conclusion that 1 the olfactory organ consists in insects, i.e. in all the 
Orthopt'era, Pseudoneuroptera, Diptera and Hymenoptera, and also in a great 
part of the Lepidoptera, Neuroptera and Coleoptera, — 1. Of a large nerve, 
originating from the cerebral ganglion and running into the antennae of these 
animals ; 2. Of a perceptive terminal apparatus, formed of bacillar cells, 
derived from the hypodermis, with which the fibres of these nerves are 
connected; 3. Of a supporting or auxiliary apparatus, which is formed by 
pits or cones filled with serous fluid, which are to be regarded as simple 
diverticula of the epidermis.’ 
It was ascertained that the organ was most highly developed in those 
insects which employ it in seeking after their food. The greatest number of 
olfactory pits and cones occur in wasps and bees ; thus the hive-bee has 
14,000-15,000 pits and about 200 cones on each flagellum. The saw-flies 
have a much smaller number. The flesh-flies and dung-flies also have 60- 
150 pits on each antenna ; while in the flies which live on plants each of 
those organs has only 2-5 pits. In general the males have the olfactory 
organs more strongly developed than the females. ( Kosmos , 1881, VoL IX.) 
The Irik of the Cuttle Fish . — M. P. Girod has communicated to the 
French Academy ( Comptes Fendus, 11th July, 1881) the results of an inves- 
tigation that he has made of the ink of the Cuttle-fish {Sepia officinalis). This 
fluid has no odour, but is of a slightly salt taste, and has an alkaline reaction. 
Under the microscope it shows, floating in a transparent serum, a multitude 
of excessively minute corpuscles, which, when put into fresh water, exhibit 
distinct Brownian movements. M. Girod finds the ink to consist of : — 
The mineral substances obtained by calcination constitute a pure white 
ash, which proved to contain lime, magnesia, soda, potash, iron and carbonic, 
sulphuric and hydrochloric acids. No phosphoric acid was present. 
The pigmentary matter , after purification by a long series of operations 
and drying at 100° C., formed a black powder with a greenish metallic 
reflection, insoluble in water, alcohol and ether, insoluble in acids and in 
alkalies. Two analyses gave the following amounts of carbon, hydrogen, 
and nitrogen : — 
Water 
Mineral substances 
Insoluble organic matter 
Extractive matter 
60 per cent. 
