April 27, 1888.] 



SCIENCE 



197 



and neck are well defined ; the body has three turns, and the tail 

 a double coil. The entire length of the serpent is about 1,420 feet- 



Near these principal mounds are several minor ones, and to the 

 south of the serpent a space which bears evidence of having been 

 both the site of an Indian village and also a burial-ground. The 

 whole tract was originally covered with timber and bushes, but it 

 was subsequently cleared and cultivated. Professor Putnam has 

 restored the grass, and has planted about the mound specimens of 

 all the trees that grow in that section of Ohio, thus adding another 

 attraction to the place. 



Several years ago Professor Putnam picked up a fragment of hu- 

 man bone that had been turned out by the plough, and at the point 

 where he found it he began to dig last summer. Very near the 

 surface he discovered a human skeleton, a few portions of which 

 only were missing. There was no doubt that this skeleton was 

 modern, — that the burial had been made by the historic Indians, 

 perhaps within the present century. A number of large stones 

 which were originally set up upon their edges about the grave — 

 one at the head, one at the foot, and several along the sides — had 

 been thrown down by the plough, but had not been much removed 

 from their original positions. 



This grave was on the edge of what seemed to be a mass of 

 stones about eleven feet long and six feet wide ; and a trench dug 

 around the edge of this disclosed several other graves, some of them 

 •deeper than the first one discovered, and covered with stones. 



Want of space forbids a detailed description of the e.xplorations 

 •of last summer. It is sufficient to say that Professor Putnam is 

 convinced that most of the graves are those of interlopers ; that is, 

 not of the Indians who built the mound, but of a later race, who 

 probably were ignorant of their predecessors, and did not icnow 

 that they were living on an old burial-ground. But the skeletons of 

 two of the supposed mound-builders were found. A section made 

 through the centre of one of the mounds disclosed the bones of 

 several ' intruders,' one of which had been disturbed by a wood- 

 •chuck ; but at a depth of si.x feet was found the skeleton of the man 

 over whom the mound was raised as a monument. The bones 

 were those of a large man, about six feet in height, and showed him 

 to be a person of massive frame. The body lay upon its back, with 

 the right arm extended at right angles, and the left arm at the side. 

 The only object found near it was a mussel-shell that lay near the 

 bones of the left leg. 



Beneath the skeleton was a layer of clay that had been placed 

 there, and upon which a fire had been kept for a long time. Near 

 the surface the clay had been burned almost as red as a brick, and 

 it showed evidence of heat to a depth of several inches. On the 

 top of the clay were the ashes from the fire, and perhaps others, 

 several inches thick ; and upon these the body had been laid, and 

 the mound erected over it. 



In another instance, in the burial-place where the first skeleton 

 was found, the body had been laid upon flat stones covered with a 

 layer of ashes, not from a fire built upon the spot, but elsewhere, 

 and which Professor Putnam suspects were produced from burn- 

 ing corn. He has not examined them carefully enough to determine. 

 There is no mound at this point. 



The explorations will be continued during the coming summer, 

 and a further report was promised for the next meeting of the 

 academy. 



A New Aerobioscope. 



A paper on ' A New Method for the Biological Examination of 

 Air, with a Description of an Aerobioscope,' prepared by Professor 

 W. T. Sedgwick of the Massachusetts Institute of Technology, de- 

 scribing experiments and inventions made by himself and one of his 

 students, Mr. G. R. Tucker, was one of the popular features of 

 Wednesday's session. Professor Sedgwick was introduced by Dr. 

 J. S. Billings of the Army Medical Museum, who spoke briefly of the 

 importance and difficulty, in cultivating bacteria from germs ob- 

 tained from the air, of being certain that nothing was obtained 

 ■e.xcept what is desired, and that what is wanted is secured. 



Professor Sedgwick gave a brief history of the discovery of the 

 ■existence of germs in the air, and of the advancement of scientific 

 knowledge on that subject to the present time. He spoke of the 

 •cultivation of germs, and described the different kinds of apparatus 

 an use for obtaining these germs. He then showed how, by a series 



of steps, he and Mr. Tucker have perfected an instrument for se- 

 curing the germs, which he calls an ' aerobioscope,' and which is 

 superior to any of those devised by European biologists. Without 

 attempting a full description of this apparatus, it is enough to say 

 that it consists of a glass tube six inches long and two or two and 

 one-half inches in diameter. It is open at one end, and continued 

 at the other at a greatly reduced size, not more than one-eighth of 

 an inch in diameter. The tube is sterilized by heating, and four or 

 five inches of sterilized granulated sugar is placed in the small part 

 of the tube. Professor Sedgwick said that it had been denied that 

 sugar could be sterilized, but he had accomplished it, raising the 

 temperature as high as 120° C. without converting the sugar into 

 caramel. Sterilized nutrient gelatine is then introduced into the 

 tube, and forms a film upon the inner surface. A portion of the 

 air the germs of which it is desired to examine is then drawn slow- 

 ly through the tube from the larger end. The germs are arrested 

 by the sugar ; so that, when the ends of the tube are closed, they 

 may be knocked down with the sugar into the larger part of the 

 tube, and are developed on the gelatine. The sugar also becomes 

 dissolved, and is a nutrient for the germs. 



Professor Sedgwick showed why sugar was a better medium for 

 holding back the germs than sand, glass wool, or any of the other 

 substances that have been used. He also described an apparatus 

 he has invented for introducing the germ-laden air into the tubes 

 and at the same time accurately measuring it, and also the method 

 of preserving the sterility of the stoppers. He exhibited a number 

 of tubes prepared for experiment, and others in which germs were 

 growing in various stages of development. 



The Systematic Relation of Platypsyllus as determined 

 by the Larva. 



Professor C. V. Riley, in his paper on the above subject, drew 

 attention to the unique character of Platypsyllus castoris, a para- 

 site of the beaver, and gave an epitome of the literature on the sub- 

 ject, showing how the insect had puzzled systematists, and had 

 been placed by high authority among the Coleoptera and the Mal- 

 lophaga, and made the type even of a new order. He showed the 

 value, as at once settling the question of its true position, of a 

 knowledge of the adolescent stages. He had had, since November, 

 1886, some fourteen specimens of the larva obtained from a beaver 

 near West Point, Neb., and had recently been led to study his ma- 

 terial at the instance of Dr. George H. Horn of Philadelphia, who, 

 at the last monthly meeting of the Entomological Society of Wash- 

 ington, announced the discovery of the larva by one of his corre- 

 spondents the present spring, and who has a description of the 

 larva in type. Professor Riley indicated the undoubted coleopte- 

 rological characteristics of the insect in the imago state, laying 

 stress on the large scutellum and five-jointed tarsi, which at once 

 remove it from the Mallophaga, none of which possess these char- 

 acters. He also showed that the larva fully corroborates its coleop- 

 terological position, while its general structure, and particularly the 

 trophi and anal cerci and pseudopod, confirm its clavicorn affini- 

 ties. He showed that the atrophied mandibles in the imago really 

 existed as described by LeConte, and that even in the larva they 

 were feeble, and of doubtful service in mastication. He mentioned 

 as confirmatory of these conclusions the finding by one of his agents, 

 Mr. A. Koebele, of Leptinillus (the coleopterological nature of 

 which no one has doubted, and the nearest ally to Platypsyllus'), 

 associated with the latter upon beaver-skins from Alaska ; also the 

 parasitism of Leptinus upon mice. He paid a high compliment to 

 the judgment and accuracy of the late Dr. LeConte, whose work on 

 the imago deserves the highest praise, and whose conclusions were 

 thus vindicated. " Platypsyllus, therefore," he concluded, " is a good 

 coleopteron, and in all the characters in which it so strongly ap- 

 proaches the Mallophaga it offers merely an illustration of modifi- 

 cation due to food-habit and environment. In this particular it is, 

 however, of very great interest as one of the most striking illustra- 

 tions we have of variation in similar lines through the influence of 

 purely external or dynamical conditions, and where genetic con- 

 nection and heredity play no part whatever. It is at the same time 

 interesting because of its synthetic characteristics, being evidently 

 an ancient type, from which we get a good idea of the connection 

 in the past of some of the present well-defined orders of insects." 



