Volume I Part 7 (1/2)

Figure 4 upper part; Figure 5 lower; and Figure 6 the perfect animal.

Between c d apparently lay the entrance to its mouth; in the little bag marked (3) its long tentacula were concealed, and below these lay a little gut marked (4) which communicated with the point (L) by a small ca.n.a.l: (1) was its swimming apparatus, and by alternate contractions and expansions of this, it took in and expelled water, and thus acquired a rapid motion, the pointed end (L) moving forwards.

Its length was 1.7 inches.

Breadth, 0.7 inches.

Thickness, 0.35 inches.

Temperature the same as the water, 65 degrees Fahrenheit.

The sketch Ill.u.s.tration 4 Diphya, Sp. gives a faint idea of the most beautiful animal of this kind which I have ever seen. It was so delicate that, with the slightest touch, portions of it came off, hence the specimen we obtained is I fear useless. The body consisted only of a central ca.n.a.l, to which were attached a number of gelatinous bags, with large lateral openings, so large that other zoophytes were caught in them, and apparently annoyed the animal; who continued throwing water out until it expelled them. The whole was surmounted by a number of the most beautiful rose-coloured tentacula: I counted eleven on it, and found four more that were torn off, but there may have been more. Its top, when looked into closely, resembled some of the sea anemones; and inside of the large bright orange-coloured tentacula were placed circular rows of smaller ones. Its body was quite transparent, with the exception of the central ca.n.a.l, which was of a milk-white colour, and terminated in a small sac of the same hue.

It moved in a direction opposite to the tentacula, by taking in water at the lateral openings of the bags, in the position in which it is represented; then bending these towards the tentacula, and expelling it with great violence.

Temperature the same as the water, 65 degrees Fahrenheit.

Length of body (to tentacula from root of tail-like ca.n.a.l) 1.8 inches.

Length of tentacula, 1.2 inches.

Length of tail-like ca.n.a.l, 0.45 inches.

Breadth, 1.1 inches.

Thickness, 0.8 inches.

Long tentacula, flesh-coloured; large tentacula, rose-coloured; lateral bags, tinged with clear amber; the rest of the animal perfectly transparent.

We this evening caught several curious little animals (Clio ?) which when taken out of the water appeared like small b.a.l.l.s of the same matter as that of which a slug is composed. Presently a little head peered out, then the body expanded itself, and finally two little things like wings were spread forth, formed of a fine membrane; they moved these very rapidly, and swam with great velocity.

We caught several small crabs, and two kinds of sh.e.l.ls, of a beautiful purple colour. (Janthina exigua.) These were very small; I have preserved several of them.

Figures 1, 2, and 3 represent different views of an animal (Salpa) slightly electrical, that we caught this evening. Figure 1 is its appearance, one side being up; Figure 2 when the other side is turned up; Figure 3 is the side view of it.

I have never before seen one of the kind electrical. Temperature the same as the water, 65 degrees Fahrenheit.

Length, 1.5 inches.

Breadth, 0.6 inches.

Thickness, 0.3 inches.

Figure 1. The intestinal ca.n.a.l terminates in a little coloured bag, generally of a bluish tinge; there is an opening at each extremity, one a little to the left of the little bag, the other, as shown in Figures 3 and 1.

November 13. Lat.i.tude 30 degrees 7 minutes south; longitude 100 degrees 50 minutes 10 seconds east.

Figure 1. Represents a little sh.e.l.l (Hyalea) which was caught this day.

Figure 2. One of the tentacula of the animal I imagine to be the Physsophora rosacea. The point which is seen obtruding at the base resembles a little nerve; it runs the whole way down the tentacula.

Figure 3. A little shrimp-like animal (Erichthus vitreus) caught on the 14th November, lat.i.tude 29 degrees 26 minutes south; longitude 101 degrees 32 minutes east. Its head was protected by a s.h.i.+eld, such as is shown in the figure.

We caught this day several other Acalepha, two of which were of the wonderful genus DIPHYA. I yesterday drew a coloured figure of the lower part of one of these animals.

This animal in its perfect state (such as we found it in today) consists of two individuals, the part of one being encased in a cavity of the other. Figures 4 and 5 Ill.u.s.tration 4 will give a correct idea of the way in which this junction is effected. The least motion separates these two parts, and each forms a perfect animal, which performs all the functions of life. This is the more extraordinary, as the containing animal is furnished with an organ not possessed by the contained, and which in their united state is used by both. Figure 5. From the little bag (f) at the bottom of the cavity (g) the receiver produces a chaplet, which traverses the ca.n.a.l in the received marked (2) in Figure 6, and which is here drawn the size of life, was sometimes expanded to the length of one foot eight inches. This organ, according to M. Cuvier, is composed of ovaries, tentacula, and suckers.

The swimming apparatus, marked (1) and (4) in Figure 6, act simultaneously; they are of a bright amber colour, and their mouth (a) and (h) are closed with little valves, nearly invisible even when in motion; the points round their upper aperture seem to form the hinges for these. In twenty seconds I counted seventy expansions and dilatations of this apparatus. The chaplet and the bag that holds it are flesh-coloured; the rest of the body is gelatinous and diaphanous. They live in families, and swim with great rapidity in the same manner as the other Acalepha.

Caught also sh.e.l.ls and crabs of the same kind as yesterday.