The female generally selects a forked twig of willow or poplar and oviposits about 400 beautiful pale yellow eggs, resembling minute musk melons. These eggs hatch about June 6th into little dull orange caterpillars sparsely covered with brown hairs; in the later moults these hairs change into black branched spines.

These caterpillars are very irritable little creatures, throwing up their heads in a threatening manner when one approaches too near them. They spin a line of silk behind them as they walk in search of a fresh leaf, these strands probably serving as life lines in preserving them from injury from a fall, or it may be these form a system of telegraphic wires.

After feeding for four or five days the old skin gets too small and requires to be shed. One can easily tell the time of moulting by their sullen, dissatisfied attitude; this period continues for a day or two, when they manage by a lot of wriggling to get rid of the worn-out skin. After the first moult the caterpillars present a little improved appearance. The head is black, with two rows of interrupted brown lines down the back and several black hairs on each segment, each tipped with a white hair. The description of the four succeeding moults is so similar that it will only be necessary to describe the last one.

Fifth moult.-Length two inches, with four branched spines, innumerable white hairs in between, and a reddish irregular-shaped spot on each segment down the back. The six front legs are black, prolegs Indian red, and anal ones black. These caterpillars do considerable damage sometimes to elm and various other trees, including poplar, willow and hop.

The next stage requires unusual gymnastic accomplishments which would drive a modern acrobat green with envy. The first thing it does is to spin a button of silk (under a ledge of a fence or a branch), tuck its two anal

Soon afterwards

legs into it and hang head downward. the first two or three segments next to the head swell, the skin splits, showing the newly forming chrysalis inside. The rent increases, and the chrysalis, acting as a wedge, succeeds in opening up the skin and pushing it down towards the anal legs.

By alternate contractions and expansions the head becomes wholly disengaged, and the caterpillar skin, now dry and shrivelled, is pressed together into a small bundle, which is its only means of support, and the difficult task which remains for the chrysalis to perform is to extricate itself from this skin and attach its cremaster to the silk above it. In order to accomplish this (which seems to require an effort beyond the power of a creature unprovided with arms or legs) the cremaster is pushed through the skin and held by it, while it searches for the button of silk. After several apparently futile attempts it finally jumps up a distance of about one-eighth of an inch and hooks its beak into it. All this time the reader will remember that the chrysalis is as soft and weak as a newly hatched bird. A comparison may here be made between a human being, which in its infancy is the most helpless of all creatures, and insects which perform such wonderful feats in their young state. The once soft chrysalis hardens and assumes the well-known grotesque shape. Perhaps these changes can be more plainly brought before the reader by supposing a fat boy, wearing a pair of sharp-pointed boots (so dear to some of our city exquisites), dressed in a worn-out but tightly-fitting sack, with his feet pushed through the sack into a loop of rope attached to the ceiling. He would require to burst the sack, wriggle it down towards his legs, having his whole weight supported by it, get his feet out of his boots and hook his toes into the same loop of rope. I do not think many athletes would care to go through a like series of

feats, but practically speaking this is what the weak chrysalis has to do.

After about twelve days in warm weather the butterfly is formed inside, the skin is rent, and the Camberwell Beauty crawls out with diminutive wings, only a quarter of an inch in length, but if you watch it half an hour you will see the wings grow to their natural size, about two or three inches from tip to tip.

It is not generally known that a butterfly attains its full size in the short space of about one hour. In about two hours it is ready to fly. After the courtship and marriage festivities are over another batch of eggs is laid and the butterflies resulting from these secure a snug retreat and hibernate until spring.

The enormous increase of these insects is prevented by ichneumons, tiny wasp-like creatures belonging to the Hymenoptera order.

3 32

The special ichneumon which attacks the Camberwell Beauty larva is called Ptermalus Puparum, a small metallic green fly; extreme length of body in., wings expanded in. It lays about 130 eggs in the mature larva. These hatch and feed inside, avoiding the vital organs; but the astonishing part is how the larva turns. into a chrysalis with 130 ichneumon naggots inside of it, each in. long. I propounded this question to Mr. A. F. Winn, an entomologist of considerable note, and he explained the mystery by informing the writer that the eggs are probably laid while the larva is hung up just before it changes into the chrysalis state; thus it is only incommoded by the ichneumon eggs and not by the large maggots.

When the caterpillar has undergone all the hard work of changing into a pupa, the ichneumon eggs are probably just hatched, and then commence to eat up everything inside the antiopa chrysalis, leaving nothing except the skin. When full fed the maggots are nearly in. long

and stout in proportion. The length of the chrysalis (antiopa) is only 1 in. and diameter at thickest part

in., so one can easily imagine how crowded 130 maggots would be in such a small space. A Montreal street car at 6 in the evening will give the reader an idea how tightly these grubs are packed together.

The maggots change into chrysalides and the flies soon. emerge by piercing one or two holes, and are just in time to destroy the larvae of the common white butterfly, while some hibernate.

2753 St. Catherine Street,

Montreal, March 1, 1901.

A. E. NORRIS.

THE FLORA OF MONTREAL ISLAND.1

(Continued from Vol. VIII., Number 1, p. 24.)

By REV. ROBERT CAMPBELL, M.A., D.D.

Now for the first time an attempt is made to collect and classify the mosses of the district. Doubtless the local species were noted' by Mr. D. A. P. Watt and others who catalogued the Acrogens of Canada forty years ago, but no distinction was made between those found near the city and those collected elsewhere. The following mosses were obtained during the summer and autumn of 1900:

SPHAGNACEE-PEAT MOSSES.

SPHAGNUM DILL.

SPHAGNUM ACUTIFOLIUM EHRH.-Peat Moss.--Savanne, St. Michel. August.

1 Being the substance of two papers read before the Natural History Society of Montreal, session 1900-1901.

SPHAGNUM CYMBIFOLIUM HEDW.-Peat Moss.-Savanne, St. Michel. August.

SPHAGNUM RIGIDUM COMPACTUM SCHIMP.-Peat Moss.— Savanne, St. Michel. August.

BRYACEE-TRUE MOSSES.

TREMATODON MICHX.

TREMATODON AMBIGUUM HORNSCH.-Petite Cote woods.

June.

DICRANELLA SCHIMP.

DICRANELLA VARIA SCHIMP.-Petite Cote woods. August. DICRANELLA RUFESCENS SCHIMP.-Base of Mount Royal.

June.

DICRANUM HEDW.

DICRANUM FUSCESCENS (TURN.) LONGIROSTRE SCHIMP.On decayed tree, St. Michel. August.

DICRANUM DRUMMONDII MUELL.-Mount Royal. July. DICRANUM UNDULATUM TURN.-Foot of Mount Royal.-September.

DICRANODONTIUM BRUCH AND SCHIMP DICRANODONTIUM LONGIROSTRE BRUCH AND SCHIMP.— Petite Cote. July.

CERATODON BRID.

CERATODON PURPUREUS Brid.—Common. May to Nov

ember.

LEPTOTRICHUM HAMPE.

LEPTOTRICHUM TORTILE MUELL.-Westmount.

LEPTOTRICHUM VAGINANS SULLIV Westmount.

tember.

BARBULA HEDWIG.

August.

Sep

BARBULA RECURVIFOLIA SCHIMP.-Mount Royal. July.