January 27, 1893.J 



SCIENCE. 



51 



into spherical balls, and when felted they sometimes alternate 

 with layers of phosphates, so that when divided the transverse 

 sections of these are found to be marked by concentric lines. 



III. The true Oriental Bezoar is found in the wild goat of 

 Persia (Capra cegagrus). and is brought to India from the Persian 

 Gulf. In appearance it is black and hard, oval in shape, with a 

 smooth surface, which has a peculiar shiny lustre. 



This stone consists entirely of ellagic acid, which is an insolu- 

 ble organic acid derived from certain constituents of the diet of 

 the Persinn goat. This acid can also be extracted from an in- 

 fusion of gall-nuts when exposed to the air. 



Bezoars were frequently set in hoops of gold or silver, having a 

 chain of some metal by which they were suspended in the liquid 

 to which it was desired they should impart their curative virtues. 

 Koemfer says : " In Persia all people of consequence possess one 

 or more of these stones preserved with great care as valued 

 treasures."' A proof of their value is found in the fact that 

 amongst the treasures sent to the Emperor Napoleon the First, by 

 the Shah of Persia, were three Bezoars valued at nearly two hun- 

 <3red pounds. 



Five hundred crowns (£135) have been given for one such stone, 

 and Tavernier mentions one, weighing four ounces, which was 

 sold for one hundred and fifty pounds. 



The diseases supposed to be cured by Bezoars were of varied 

 character, such as epilepsy, palpitation, vertigo, contagious fevers, 

 etc. It is said to have been a custom in Persia to take a dose of 

 powdered Bezoar at the beginning of the year to protect the body 

 from poi.son for the succeeding year. 



They may have been useful perhaps in some cases, owing to the 

 amount of bile contained in them, and also because they were 

 sometimes steeped in infusions of active medicinal plants. 

 IV. The Occidental Bezoar. 



This is found in the goat of Peru and India, and, as a rule, it 

 is larger, lighter in color, and for the most part without the 

 peculiar black metallic lustre of the true Oriental stone, and is 

 of much less value. The chamois yields what is known as Ger- 

 man Bezoar, and another similar stone is found in the llamas of 

 Peru. 



The high price of the Oriental Bezoar led to numerous imita- 

 tions, for the mosc part made of chalk and pipe clay, frequently 

 gilded to give the high polish of the Eastern stone. 



By putting butter of antimony under the action of nitric acid 

 an artificial Bezoar can be made, and other imitations were made 

 of vegetable resin identical with the litho-fellic acid of M. Goebel, 

 which he found in a calculus examined by him. These stones 

 are sometimes called resino-bezoardic concretions. 



The snake stones of the Portuguese were probably made by the 

 Brahmins, who pretended that they were taken from behind the 

 head of the Cobra da Capello. They were called Pedra di Cobra, 

 and were made of calcined bone-earth finely powdered and mixed 

 with musk and aromatic gums. They were probably of use when 

 applied to wounds, although not quite in the way imagined, for, 

 being highly porous and absorbent, when applied in quick succes- 

 sion to a recent snake-bite, these stones wouUI naturally draw out 

 the poison by capillary action ; when one stone fell off another 

 would be supplied until the wound was sucked dry. Koemfer 

 says 38 stones were needed to be applied to effect a cure. 



Fossil Bezoars are found in Sicily in sand and clay pits. They 

 are concretions of a purple color, around some usually organic 

 body, and are of the size of a walnut. 



V. Concretions of phosphates of magnesia and ammonia. The 

 consideration of these calculi would hardly come within the limits 

 of this paper. 



VI. Ambergris. 



Concretions found in the Spermaceti whale. This substance is 

 found also floating on the sea upon the coasts of Japan, Coro- 

 mandel, and Madagascar. It is of very light specific gravity, 

 ash-colored, with black veins and spots. It is supposed to be a 

 product of disease, as it is only found in dead or sickly whales. 



One more so-called Bezoar may be mentioned, and then, as far 

 as is known, all the various kinds will have been touched upon. 



In the Malay Peninsular there is sometimes found in the cocoa- 

 nut a stony concretion, properly called Callapitle, which is worn 



by the Malays as an amulet of great value. This is so like Bezoar 

 that it is sometimes mistaken for it, although a purely vegetable 

 product. 



THE STUDY OF MOULTING IN BIRDS. 



BY WITHER STONE, M.A., CONSERVATOR, ORNITHOLOGICAL SECTION, 

 ACADEMY OF NATURAL SCIENCES OP PHILADELPHIA. 



The question of change of plumage in birds, even in our com- 

 monest species, has never received the attention that it deserves, 

 and, considering the number of ornithologists which we now have 

 in the United States it seems strange that we know so little of the 

 matter. 



Perhaps now that the field for the discovery of new species or 

 races of North American birds is narrowing so rapidly, attention 

 will be turned to the study of moulting and other none the less in- 

 teresting phases of bird life. Comparatively little material seems 

 to have been gathered as yet for the proper discussion of plumage 

 changes, for in almost all the private collections of bird-skins 

 that I have examined I have been struck with the lack of speci- 

 mens illustrating seasonal changes of plumage, the bulk of the 

 material being either adult spring birds or fall birds which have 

 completed the moult. 



The reason for this is easily seen, as in August, the season 

 when most birds experience their complete moult, collecting is by 

 no means easy work. The birds themselves are quiet and inac- 

 tive, which renders them inconspicuous and hard to find; then, 

 also, the specimens secured during the moulting season are diffi- 

 cult to prepare satisfactorily, while the heat of mid-summer 

 renders immediate preparation necessary. Such obstacles should 

 not, however, stand in the way of the collector and those making 

 local collections of birds should aim to have a sufficient series of 

 each species to show all its seasonal changes of plumage. 



Having been recently engaged in examining some interesting 

 series of moulting birds, a few words on these and the question of 

 moults in our passerine birds in general may not be out of place. 



Change of plumage in birds, as is well known, takes place in 

 two ways (1) by the acquisition of an entirely new set of feathers 

 and (3) by an abrasion or wearing away of portions of the old 

 feathers. 



As a matter of fact both of these methods are employed by all 

 our birds though the amount of change and the number of 

 changes during the year vary in different species. 



In all our birds there is a moult of all the feathers late in the 

 summer or early in September, when the breeding season is over, 

 and the feathers are in the poorest condition. The moult at this 

 season is an obvious necessity, as without it the birds would be 

 unable to accomplish their autumnal migration and would be 

 but ill prepared to withstand the cold of winter. Specimens 

 secured just before this moult takes place are in a wretched condi- 

 tion, many of the tail feathers are reduced to mere spines and 

 the wing feathers are often more or less broken while the body 

 plumage is very much worn and some patches are often entirely 

 lacking. 



In effecting the complete moult the feathers are renewed a few 

 at a tinae in a regular sequence, and the utility of this can easily 

 be seen for if the old plumage was all lost at once the bird would 

 be unable to fly forsome days and would in all probability perish. 

 On the wings the moult begins with the middle feathers and ex- 

 tends out^vard and inward, corresponding feathers being lost 

 from each wing simultaneously. At the same time the feathers 

 on the sides of the breast, centre of the back, and the wing 

 coverts are renewed. Male bobolinks taken in this state show the 

 process very clearly, and the bright bands of buff forming an in- 

 verted V on the breast stand out in relief against the dull black 

 of the old summer plumage. The change of plumage on the 

 other parts of the body follows rapidly, and the new dress is 

 donned in a remarkably short time, with the exception of the 

 last wing and tail quills. 



The second method of changing plumage — by abrasion — is 

 best seen in birds having parti-colored plumage where the centre 

 of the feather is of one hue and the margin of another. Of 

 course, abrasion occurs in all birds, but when the feathers are 



