634 PHILOSOPHICAL TRANSACTIONS. [aNNO 1775. 



hopes of ever arriving at the end of this pursuit. The scarcity oT high tides, 

 the vicissitudes of seasons, and other similar impediments, make it less wonder- 

 ful that a series of years should often elapse before it is possible to present the 

 curious with any discoveries of which they might avail themselves, either by 

 analysis, combination, or analogy, and thereby furnish general views and a chain 

 of ideas leading to a new field of discovery, the usual effect of contemplation 

 I shall here communicate some of the ideas that have been suggested to me by 

 my last experiments. 



How many are the animal functions, which seem to depend on sensibility 

 and irritability ; and yet how little are these faculties understood ? how ignorant 

 are we of their cause ? The nerves seem to be the chief, perhaps the only 

 organs of sensibility in man, and the muscular fibres to be the principal seat of 

 irritability ; yet how many are the doubts entertained concerning the parts that 

 are and are not endowed with one and the other ! how false and erroneous the 

 conclusions relating to the effects they produce, notwithstanding the many ex- 

 periments made on animals, whose interior structure is the most similar to our 

 own ! It is then from accurate observations on such animals as bear the least 

 resemblance to our species that we may hope for new discoveries. The sea 

 anemonies are exceedingly gelatinous, and at the same time so irritable, that 

 even light affects tliem, though to all appearance destitute of eyes. Might not 

 the rapid and singular reproduction of the parts of this animal be attributed to 

 their gelatinous texture ? and if so, may we not reasonably conclude, that the 

 reproduction of our vascular and fleshy parts in the consolidation of wounds, is 

 in great measure owing to such a gelatinous matter ; and should we not seek for 

 means to increase or diminish the quantity of that matter as circumstances may 

 require. If it be true, that earth and a gelatinous substance are the constituent 

 parts of the muscular fibres of such animals as we are best acquainted with, and 

 that only the latter are capable of irritation ; doth it not follow, that the gelati- 

 nous nature of the sea anemonies is the true cause of the effect produced on 

 them by the impression of light ? and may we not conjecture, from the very 

 gelatinous nature of these animals, and from their being affected by light on 

 every part of their bodies, but more particularly on those that are recently cut ; 

 may we not then, from hence conjecture, that the gelatinous part of the mus- 

 cular fibre is the only one capable of irritation in ourselves ? Might not these 

 animals, by a sober use of analogy, or by new experiments, lead us to a more 

 perfect knowledge of those singular enemies to man, the tape, the hair worm, 

 and the sea-dragon ? 



I continued to observe the inferior half of a purple anemony of the first spe- 

 cies, which I had cut in two on the 12th of July 1772, and which was alive on 

 the 8th of April 1773, the day on which I concluded my former essay: it ap- 



