338 



NATURE 



[August lo, 1893 



students of forestry. The annexed table of contents 

 explains its general scope — ■ 



Section First. Protection of Woodlands against In- 

 juries due to Inorganic Agencies. — Chap. I. Damage 

 caused by unusually High or Low Temperature, (a) 

 Frost, {b) Heat. II. Damage caused by Atmospheric 

 Precipitations, {a) Rain, (b) Snow, (c) Hoar-frost, ice, 

 hail. III. Damage caused by Aerial Currents. IV. 

 Damage caused by Lightning. V. Disadvantages arising 

 from Unfavourable Soil and Situation, {a) Excess of 

 moisture ; wetness, {b) Deficiency of moisture ; dunes, 

 sand-drifts. VI. Diseases of Timber Trees. 



Section Second. Protection of Woodlands against 

 Injuries due to Organic Agencies. — Chap. I. Damage 

 caused by Plants, (a) Noxious forest weeds, (b) Para- 

 sitic plants. II. Damage caused by Animals, (a) 

 Mammals, (i^) Birds, (c) Insects, (a) On coniferous 

 trees principally, (b) On broad-leaved trees principally. 



Section Third. Protection of Woodlands against 

 Human Agencies. — Chap. I. Protection of Forest Boun- 

 daries. II. Protection against Misuse of Rights or 

 Servitudes. III. Protection against Forest Offences and 

 Misdemeanours. IV. Protection against Forest Fires. 

 V. Protection against Damage by Smoke and other 

 Atmospheric Impurities. 



NORTH AMERICAN BUTTERFLIES. 



Brief Guide to the Common Butterflies of the United 

 States and Canada. Being an Introduction to the 

 Knowledge of their Life-histories. By Samuel Hub- 

 bard Scudder. (New York : Henry Holt and Co., 

 1893-) 



The Life of a Butterfly. A Chapter of Natural History 

 for the General Reader. (Same author and publisher.) 



IN the two small volumes before us Dr. Scudder, 

 the author of the greatest monograph on any limited 

 butterfly-fauna that has yet appeared (" The Butter- 

 flies of the United States and Canada "), has attempted the 

 no less useful task of popularising the subject for the less 

 advanced student. 



Far more attention is paid in America than in Europe 

 to the life-histories of insects, and the plan of Dr. 

 Scudder's " Guide " is sufficiently indicated by the author 

 in his preface. " I have accordingly selected the butter- 

 flies — less than a hundred of them — which would almost 

 surely be met with by any industrious collector in the 

 course of one or two years' work in the more populous 

 Northern States' and Canada . . . . As the earlier 

 stages of these insects are just as varied, as interesting, 

 and as important as the perfect stage, descriptions are 

 given of these .... only such stages as would be 

 more commonly met with being fully described, and the 

 egg and earliest forms of caterpillar omitted as rarities, 

 and also as too difficult for the beginner's study." 



Those who know the thorough character of Dr. 

 Scudder's work will not be surprised to learn that even 

 within the narrow limits laid down, the book contains a 

 far larger amount of general information than would be 

 found in almost any popular European manual on a 

 similar subject. Not that such information respecting our 

 European butterflies does not exist, but it is scattered 

 NO. 1 24 1, VOL. 48] 



through thousands of volumes of periodical literature^ 

 and has hardly yet been properly systematised for the 

 advanced student, much less for the beginner. 



The introductory portion of Dr. Scudder's work consists- 

 of general information respecting butterflies in their 

 various stages, separate keys to the American genera, 

 both for the perfect insect and for the caterpillar and 

 chrysalis, an explanation of neuration with a diagram^ 

 &c., &c. 



In the body of the work each species occupies from 

 one to two pages. It is first described as butterfly^ 

 caterpillar, and chrysalis, and then a full account of its 

 life-history, habits, localities, times of appearance, &c., 

 in all its stages, from egg-laying onwards, is given in 

 larger type. An appendix contains instructions for col- 

 lecting, rearing, preserving, and stuffing, extracted from 

 one of Dr. Scudder's former works. 



Dr. Scudder is rarely to be found tripping, but we 

 think that the section on the senses of insects is hardly 

 abreast of our present knowledge of the subject. On 

 p. 23 he says, " The sounds made by butterflies are 

 apparently due simply to the rustUng of the wings." If 

 he will refer to the work of an eccentric writer, but a good 

 observer (Mr. Swinton's " Insect Variety," pp. 1 12-127}, 

 he will find a good deal of information about the stridtt- 

 lation of butterflies. 



The second work which we have to notice, though 

 smaller, is perhaps of greater interest to the European 

 entomologist. It deals with Anosia Plexippus, the 

 Monarch or Milk-weed Butterfly, one of the largest and 

 most abundant of North American butterflies, a migratory 

 insect which is rapidly extending its range over the warmer 

 parts of the world. 



It has been selected as a butterfly whose life-history 

 presents more interesting points than that of most others 

 (though other butterflies are, of course, referred to : n the 

 course of the work), and the following are some of the 

 principal points which Dr. Scudder discusses in referencft 

 to it : the tongue, course of life, vagrancy, criti(a|' 

 periods, mimicry, scent-scales, insect vision, the fore- 

 legs, the position of the chrysalis, the proper name, &c. 



It is now pretty well ascertained that this butterfly 

 has as regular an annual migration as birds in North 

 America from south to north and north to south. No 

 lepidopterous insect probably possesses the habit to any- 

 thing like the same extent ; for the migrations of the 

 day-flying moths of the genus Uratiia, though regular, 

 are confined to comparatively narrow limits in the 

 tropics. 



We will now notice a few points that have struck us 

 in glancing through the book. At p. 64, Dr. Scudder 

 says : " There were certainly no butterflies here when 

 the country was flooded with ice." Is not this too 

 sweeping a statement .? Have not our Arctic explorers 

 found butterflies as far north as they have yet succeeded 

 in penetrating ? 



It is pretty well known that newly-hatched caterpillars 

 generally devour the shell from which they have just 

 emerged. This has usually been regarded as merely an 

 odd habit ; but Dr. Scudder suggests that its real object 

 may be to avoid betraying the proximity of the larva to 

 its enemies by leaving the empty eggshell as an indication 

 of its presence (p. 70). Scent is considered by Dr. Scudder 



