"SAO PAULO, BRAZIL, 26th January, 1879.

"My dear Sir, I have received your letter of Nov. 15th, and the copies of my paper on 'Experiments with Venomous Caterpillars.' The plate is beautifully executed, and it is a satisfaction to see one's work so excellently carried out.

"This season does not appear to be nearly so good a one as the last. We have had unusually cold weather up to the end of December, and now the rain is excessive. Already thirteen inches this month! The wet, no doubt, must cause a great many specimens to perish.

"Morpho Laertes is just beginning. Last year I noticed specimens on January 1st. I have a number of the chrysalids, one of which has come out. A lady in Rio, who has a very extensive collection, pointed out to me that the females of M. Laertes, in São Paulo, are much more richly marbled on the underside than those of Rio de Janeiro. In the males there is not so much difference. Some of the females I obtained last year are very handsome.

"At the end of December I found a cluster of caterpillars of a Papilio, in the trunk of a Tangierine orange tree. There were about forty specimens in the cluster. The scent organs are very largely developed, and I observed that they had the power of flinging a tiny drop of colourless fluid on to any offending object. This fluid has a very disagreeable and pungent smell, and would no doubt prevent the caterpillar being eaten by any bird. But they seem to be very much attacked by an ichneumon fly. Out of seven chrysalids, only three have come to perfection. The odour of the caterpillars is so strong that I could smell them at a considerable distance from the tree.

"The butterflies have made their appearance, having been twenty-three days in the pupa state. It is a beautiful insect;

the anterior wings are black, shaded with grey, and the posterior black, with a pinkish-crimson spot, shot with purple. This makes thirty-eight species worked out from the caterpillar. I have a dozen chrysalids of a species of Morpho, which I am anxiously watching, hoping they will turn out Achilles.* In any case they are sure to be magnificent creatures, for they are very large and robust, and all the family of Morphos are lovely insects. I was fortunate enough to find a large cluster of the caterpillars, just ready to change, great stout fellows of a brick-red colour, with tufts of black and of white hairs, the black ones being barbed, and coming out if touched with the back of the hand, and causing great irritation. Before changing they turned completely green, which is a remarkable change from red. The chrysalis is a dull green, covered with a white bloom, that easily rubs off. The caterpillar emits a disagreeable choking odour when irritated, similar to that of Morpho Laertes. But it is quite distinct, and I could tell the two species with my eyes shut by the peculiar smell. This species feeds on a climbing plant (one of the Bignoniaceæ ?) while M. Laertes feeds on a papilionaceous tree.

"I think it is time I began to send you some of the results of my observations of the metamorphoses, and I will begin by a paper on that most interesting moth whose larva lives in the hammock-like case. The drawings, you will observe, are not properly finished; but I hope they will convey some idea of what the creature is like. The fact of the matter was, that after I had drawn the hammocks, I left the drawing to finish when I had more leisure; but, unfortunately, when I went to work again, I found the paper had got so mildewed that it was impossible to do anything with it. So I could only just outline the moth and leave the rest alone. If you place

the three pieces together, you will see what the drawing was intended to be.

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1st February, 1879. "P.S.-Since writing the above, two more moths have arrived at perfection, bringing the list up to forty species. They both belong to the same genus as the venomous one with which I made the experiment (probably Lagoa). One of them is the curious hairy caterpillar, like a Skye terrier (No. 42), of which I sent you a rough sketch last April. The moth is beautifully marked, the veining of the wings being clear and striking.

"A few days ago I found some young specimens of a spiny caterpillar (Citheronia ?), and I killed one by putting a drop of benzine on it. Another one, which was just about to change its skin, I also dropped benzine on. But it did not seem to affect it in any way. Next day I dropped some more on it. The day after I found it had changed its skin, eaten it, and half devoured the other caterpillar that I had killed with benzine!

"This caterpillar is remarkable for the great changes of colour from the young to the full-fed condition. At first it is black, with a brown mark in the middle, and the anterior segments are armed with curious long spines, with a crescentshaped top. After the second (?) change the spines lose the crescent, but are very long and black. After the last change, the general colour is a smoky pink; the spines are nearly colourless and transparent. The colour then changes (without casting the skin) to a beautiful green; the spines become short and bright red, tipped with black.-E. D. J.