363

Hobart Town

1835 February

Planaria 3518: 19: 20: 21: [illeg] Leaches analogous fact.— General shape as formerly I found beneath a dead rotten tree in the forest a considerable number of this animal. the decaying wood was only slightly moist.— Color dirty "honey yellow", with central narrow dark brown line on back. on each side a broarder band of pale "Umber brown". beneath snow white & dotted. Both extremities pointed; the anterior one most elongated, extremity slightly turned up & furrowed on under surface. Black points situated around whole margin of foot, but much most abundant near Anterior extremity. Two orifices on inferior surface; the anterior one of them is placed in about middle of the body, & the posterior rather nearer to the first than to the extremity of the tail. Whilst the animal crawls these orifices are about .2 of an inch distant, but when at rest not above half of this.— The posterior orifice is plainest to be seen, more circular & sub. margined. the anterior one only consists of a transverse slit.— Close Before (or nearer to the head) this, the cup shaped organ is situated, its mouth is widely extensible into a conical membrane. the base of this funnel or mouth depends from

364

Hobart Town

1835 Feby

the central vessel, which runs towards anterior extremity. Animal placed in weak spirits of wine, this organ is protruded.— On each side of whole length of body that opake branching structure is visible, which has formerly been described.—

A good sized individual crawling was 1.5 of an inch long, but when at rest only .8.— Manner of crawling &c similar to what has formerly been described.— I kept some specimens alive in a saucer with rotten wood from Feby 7th to April 1st, when apparently from the excessive heat of the latitude which we then entered, they gradually sickened & died.— during this period they some increased in size; the most perfect one the day before its death, I found with the skin on its back ruptured & the cup shaped organ partly protruded through the hole. I observe they have a particular dislike & immediate apprehension of the light, directly crawling to the under side of bits of wood.— Having neglected to put any water with the rotten wood, it became one day perfectly dry. the largest & only perfect

365

Hobart Town

1835 Feby

Planaria specimen contin did not suffer any injury.—

Feb. 10th Cut an individual into two pieces, without attending to where the section was made (possibly it at the anterior orifice). On the 16th both ends quite lively, wounds healing; one orifice manifest in posterior half, but more in the anterior. March 6th. Posterior half quite lively, the posterior orifice visible, wound unhealed, crawls with in the proper direction: Anterior half with its truncated end quite healed & pointed, slightly pink.— I can see no orifice on the lower surface.— These specimens were lost by neglect.—

March 6th On same day (6th) cut another specimen into nearly equal halves, one having the two orifices & the other none.—

20th The posterior half had become a perfect animal, the wound quite obliterated; the new anterior extremity was rather suddenly pointed & of a slight pink color. The anterior extremity half resembled in figure to a perfect animal.

31st The posterior half in no way to be distinguished

366

Hobart Town

1835 Feby

Planaria from any other individual.— The anterior extremity half had increased considerably in length since the 20th.— Near to its tail, by the aid of transmitted light, a pear-shaped clear space was most distinctly visible. [sketch] it was united to a short clear vessel or space which lead to the tail.— Within the pear-shaped clear space, an opake cup-shaped could be obscurely distinguished. But by no mean could I discover a trace of any orifice on the corresponding part of the lower surface or foot.—

Their death was hastened by this last examination It is impossible to doubt, if the hot weather had not killed all the specimens, that in time the cup shaped organ & its orifice would have been produced & the animal completed, similar in every respect to the one produced by the Posterior half.— Thus we see these 25 days sufficed to complete one animal in every respect & another in its external form & partly in its internal structure.— In the first case, the fact of the wound in the posterior half not being (a) healed after 26 days may perhaps be accounted for by supposing the section was made at the

[366v]

(a) point of the anterior orifice.—

I must here mention that at New Zealand I saw a species of this genus, but lost it in bringing it home.— We thus see that in the Southern hemisphære, America, New Zealand & Van Diemens land all possess this curious family of terrestrial animals.

In the Isle of France I also saw a small specimen beneath a stone in the mountain of La Puce.— May, 1836.—

Anyone accustomed to [view] Planaria is surprised at being terrestrial.=

Reproduction of cut body same in terrestrial & aquatic species.

Duges

p. 12 movement well described.

p. 14 In Derostoma œsophagus apparently not essential.

p. 15 P. tremellaris marine spec. [illeg] folded in zigzag.

p. 28 aquatic species allow water to act on their lower surface, apparently for aeration.

Has observed tenacity of life in trunk.

p. 29 softening of body not fluid.— dissolution of body.

p. 30 cicatrica Diaphane.

p. 34 In P. tremellaire " pores genitaux rounded".—

p. 35 eggs placed between branches of Intestinal case.