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Gossamer Spider (a) 462 Sailing between M Video & B Ayres on Octob. 31st the rigging was coated with the Gossamer web: it had been a fine clear day with a fresh breeze.— The next morning the ropes were equally fringed with these long streamers.— On examining these webs I found great numbers of a small spider.— On the second day (which was calmer) there must have been some thousands in the ship.— When first coming in contact with the ropes, they were seated on the fine lines & not on the cottony mass.— This latter appears to be only the separate lines collected by the wind.— From the direction of the wind must have travelled at least 60 miles from the Northern shore.— They were some full grown & of both sexes & young ones; these latter, besides being of a smaller size, were more duskily coloured.— Spider eyes 8 equal in size, seated on anterior end of thorax, viz. [sketch] the lateral eyes, or those on sides of the quadrilateral figure, are very close & seated on a common small eminence.— Cheliceres cylindrical, tapering at extremity; claw folding transversely & received between spine (with this it cleans its legs): Maxillæ, when mouth is closed incline on the Labium: when open are shaped each thus [sketch] inner side straight, summit rounded truncate, outer inclined: Labium small, triangular, pointed: Legs four anterior ones longest, & 3d pair shortest; thin long:— Thorax Palpi, with organs in male much developed & coloured black:— Thorax heart shaped, truncate anteriorly, this part black, the rest red:—

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(a) October, answering to our Spring.— when they are abundant in England

November 25th During the last week, every object both on the ship & on shore (Monte Video) has been occasionally covered with Gossamer: Invariably I have observed great numbers of the same small spider.— I frequently observed them sail away from any small eminence: I imagined that before protruding upward their abdomen & sending forth the web, they connected by delicate lines their feet together ?? I cannot actually say that the Spiders ever rose, but they laterally sailed from their position with unaccountable rapidity.— But even if they did ascend, I should almost imagine the ascending current on a calm & hot day would be sufficient to account for it.—

Decemb 4th Lat 40°.20′ S. There were great numbers & spiders on the rigging, we being about 20 miles from the shore:

December 1833 I saw at St Fe Bajada a brown coloured spider, I should think 3/10 of inch long (appeared very large) & from its general form a Laterigrade Citigrade.— standing on summit of Post it darted 4 or 5 lines from its anus, which glittering in the sun looking rays.— they were a yard or two long & by a gentle current hardly perceptible were carried upwards & laterally.— The threads curling & diverging.— the Spider suddenly loosed its hold & sailed out of site.— The air is seldom so calm that a delicate vane like spiders web is not affected.— on a hot day, would not the currents of air flow upwards; no ordinary vane would from its specific gravity would show a slight tendency to this motion.— Yes, [illeg] mirage & tremulous shadows always occurs on any warm day.—

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Gossamer Spider (b) (a) Abdomen pointed, oval, coloured dusky red: Filières projecting in a bunch at posterior extremity; each one cylindrical, short.— Length of body .1: When not moving, the legs are elevated: its motions rectigrade: I know not whether this spider belongs to the Tubitetes or inæquiletes: it does not agree with any of Lat: genera:— These little spiders, after alighting on the ropes, were in their habits very active; They frequently let themselves fall from a small height & then reascend the attached line.— Occasionally when thus suspended, the slightest breath of air would carry them out of sight on a rectangular course to the line of suspension.— I never saw them rise at all: They formed an irregular net work amongst the ropes: Could run easily on water: Lifted up their front legs in attitude of attention.— Seemed to have an inexhaustible stock of line web: With their Maxillæ protruded, drank eagerly water; this curiously agrees with an observation of Dr Strack:─

The above mentioned facts in the occurrence of numerous (sufficient I think to account for the Gossamer) spiders of same species but different sexes & ages, on their webs, & at a great distance from the land & therefore liable to no mistakes demonstratively proved that the habit of sailing in the air as much belongs to a division in Spiders as diving in the water does to Argyroneta: We may

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(a) From not clearly understanding the characters drawn from the Filières:—

(b) Body & legs covered with fine down

In the Spring of 1833 when about 60 miles off the mouth of the Plata, several came on board in their web. appear (827) exactly same species: one is an old male

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Gossamer spider then reject Latreilles supposition that the Gossamer in the air owes its origin to the web of young web of Epeira & Thomisa.— Still more so that of Hermans (fils) that it belongs to an Acarus (Trombidium).— As far as the characters of the eyes goes, this Spider agrees with the sort described by Strack as coating the ground.— I mention (Page 49) a spider under the name of Theridion (which shows the same position of eyes), as every where coating newly turned up ground.— I never however saw the aerial Gossamer here there: Kirby thinks that Stracks spider & those Dr Lister saw mount in the air are the same. Perhaps it may hereafter be shown, that if not identical the two sorts are closely united (viz aerial and terrestrial gossamer).— The celerity with which this spider voluntary can fall, shows, that light as its body seems, it must have considerable specific gravity: it is difficult therefore to understand in what manner the rapid rectangular motion was effected:—

Chara 476 Common in running water: In the microscope could clearly perceive a slow circulation of round particles.— Branches finely striated, with distant spines, parallel to these the globules moved: In same manner as the Striæ, a colourless line encircled spirally the stem; but on one side of this the current ascended & on the other descended. So that in the equal spaces marked by the spine on the stem; the current alternately was