TRANSACTIONS OF THE SECTIONS. 123 
7. Prolific females are exempt from exuviation, that their spawn adhering ex- 
ternally may not be exposed to injury. 
8. The young of many crustaceans, which bear no resemblance to the parent, attain 
symmetry and perfection through the medium of successive metamorphoses. 
Notice of a Tissue spun by Caterpillars. By James DENNISTOUN. 
In the early part of this century there lived at Munich a retired officer, Lieutenant 
Hebenstreit, who amused himself by experiments on the means of giving consistency 
to the gossamer produced by caterpillars, which is occasionally seen blown about in 
flakes over the fields in Germany, and he was at one time sanguine of rendering it 
available as a material for ladies’ dress. It is said that his plan was to prepare a 
paste of lettuce or other leaves beat up with butter, and, after spreading it thinly 
over a smooth surface of stone or wood on an inclined plane, he placed at the lower 
end a number of chenilles or caterpillars of the proper species. ‘These animals gra~ 
dually ascended the incline, devouring the paste, and depositing as they proceeded a 
sort of tissue until the whole surface was uniformly covered with it. He is reported 
to have produced open-work designs by drawing the pattern with a hair pencil dipped 
in olive oil beforé the animals began to work. These I never saw, but I have seen 
one veil on which were some letters exactly resembling a water-mark on paper, the 
secret of which I do not know. The inventor pursued his experiments with great 
secrecy, in the hope of turning his invention to valuable account ; but finding this 
impracticable, it appears that he produced but very few specimens, which are now 
preserved in various museums on the continent. I have seen two besides my own, 
which I procured at Munich in 1837 after having advertised for it several months. 
The objections to using this tissue seem to be chiefly its exceedingly flimsy quality 
and its very adhesive properties, which render its management and preservation ex- 
tremely difficult—attaching itself closely even to the smoothest surfaces, from which 
it can be separated only by the breath. My veil is about 42 inches by 24. One of 
26% by 17 inches is said to have weighed only one grain and a half. Another con- 
taining nine square feet is mentioned as weighing 43 grains, while the same surface 
of silk gauze weighed 137, and of fine lace 2623 grains. A notice of these tissues 
appeared in Chambers’s Journal about ten or twelve years ago. It would seem that 
the art was in some degree known at an earlier period, and occasionally practised 
in convents, where coloured drawings on small bits of it are said to have been made. 
T have seen in all four of these on the continent, and two or three on which impres- 
sions from copper-plate had been taken—always of sacred subjects. One of the 
drawings is in my possession, about 7 inches by 5, executed apparently in the last 
century, and I have seen one dated about 1770. 
On the European Species of Echinus, and the Peculiarities of their 
Distribution. By Professor Epwarp Forsss, F.R.S. 
When the author published his account of the British Echinodermata, he laid great 
stress on the distinctive characters furnished by the sculpture of the spines in each 
species. In this communication he endeavoured to show that these characters are 
of the most certain kind, that they bear definitive relations to the more important 
features of the organization of the test, and that through them we are enabled easily 
to recognize even the most aberrant varieties of each species. 
In the work alluded to, five species of Echinus were enumerated as British: viz. 
E. sphera, E. Flemingii, ΕἸ. miliaris, Εἰ. neglectus, and ΕἸ. lividus. Although during 
the ten years which have passed since the publication of this list, the most active 
exploring researches have been carried on in our seas, only two additional forms 
have been brought to light. : 
One of these is the Echinus Norvegicus of Duben and Koren, a pretty species of 
small size, first observed on the Norwegian coasts, and since dredged by Mr, 
McAndrew off the shores of Zetland. The other appears to be identical with the 
Echinus Melo of the Mediterranean. It was discovered on the coast of Cornwall by 
