OBSERVATIONS ON THE ARGONAUT. 103 



vours ; to examine the relation of the mollusc with its shell 

 the second ; and the third to accompany it in its develope- 

 ment from the egg through its entire growth. But how to 

 prosecute so difficult a series of observations ? The Port of 

 Messina, daily frequented by me in search of marine objects, 

 offered opportunities and means which perhaps no other situ- 

 ation could present. For this object I thought of cages, 

 which were constructed under my direction ; they were eight 

 palms long and four broad, with a convenient interval (three 

 or four lines) between the bars, which allowed the water to 

 enter freely when placed in the sea, whilst the escape of the 

 animal was prevented. I placed the cages in a shallow bot- 

 tom in the sea near our citadel, in a spot where I could exa- 

 mine them without disturbance. I inclosed in them a num- 

 ber of living argonauts, which I took care to supply every 

 two or three days with both naked and testaceous molluscs 

 for food. Fortified with invincible patience, I never once 

 thought of desisting from the undertaking, although many and 

 many times my experiments met with no fortunate result. — 

 It was only after several months that I succeeded in clearing 

 up my doubts, and in seeing my researches crowned with 

 success. 



With regard to the structure of the mollusc of the argonaut, 

 as no one is ignorant of what authors have said on the sub- 

 ject, it will not be out of place to recount what I have ob- 

 served as singular, or not described by others, doubting that 

 some essential particulars in the history of this animal may 

 have escaped many naturalists. 



The cephalopod of the argonaut is furnished with eight 

 arms, having on each two rows of suckers ; the first two arms 

 are more robust than the others, and should be so, because 

 they serve as masts to support the sails, which, spread out, 

 act before the wind as such. At the base they have, on the 

 inferior sides, the double row of suckers like the other six ; 

 but from the inferior row, at about an inch from the base in 

 adults, a rather fun-owed membrane begins to develope itself, 

 which extends as far as the tip of the arm, and holding it 

 bent, it can no longer follow the office of a rowing arm, but 

 as every one knows, it is employed by the animal as a sail. 

 But here I am glad to observe that these sails (for so we will 

 call them) attached to the sailing arms are so large, that when 

 turned backwards and pressed against the shell they can en- 

 tirely cover and protect it. Thus, as far as I can conclude, 

 the true office of these sails is exactly that of keeping them- 

 selves applied to the shell at all times, in reserve for the mo- 

 ment when the animal, coming to the surface of the water, 



