circulating in their veins. These last include "insects, molluscs, crustacea, and creatures with more than four feet."
Note 4, p. 111. And hence the difficulty of determining, &c.] If the site and structure of the olfactory sense, in the lower forms of life, are still somewhat conjectural, it may well be supposed that the smell in non-breathing animals was, in that age, although seen to be a fact, inexplicable. But yet, although anatomy could not then determine the seat of the sense, it might have been conjectured that, as such creatures are obviously affected by odours, there must be some other inlet for them than that through which impression is made upon animals; and the detection of this mode of perception, would have been another instance of homologous physiology. Aristotle[1], following Plato, placed the seat of the smell and other senses in the neighbourhood of the heart; but "the organ was said to be located, suitably, between the eyes."
Note 5, p. 112. The olfactory organ in man, appears to differ, &c.] The analogy is obviously faulty, as it seems to imply that the olfactory, like the respiratory organs, are furnished with a cover, by the raising of which odours gain access to the sense; or rather, owing to the intricacy of the parts and imperfect anatomical knowledge, the epiglottis has been associated with the velum and posterior fauces. It could answer no purpose, then,
- ↑ De Part. Animalm. II. 30. 9. 17.
