632 



SCIENCE. 



[Vol. II., No. 40. 



euchym), which arranges itself so as to form the 

 partitions of the hody, dividing the disintegrated 

 yolk-mass into separate accumulations, which, cora- 

 hining with the yolk-cells swallowed, gradually 

 assume the form of the intestine with its coeca. 

 No entoderm exists, unless two cells at the base of 

 the proboscis are a remnant of it. During these 

 changes the nervous system appears, and the sheath 

 around the proboscis is developed. Metschuikoff 

 advances the opinion, that the yolk-cells swallowed, 

 though not derived from the ovum, and being foreign 

 bodies, nevertheless become the cells of the apparent 

 entoderm of the adult. He further believes that the 

 nervous system is derived from the mesoderm. If 

 Metschnikoff is correct in maintaining, that, first, 

 there are no epithelial germ-layers; second, the cleav- 

 age-cells are mixed with and embedded in a foreign 

 substance; third, foreign cells form the entoderm, 

 there being no embryonic entoderm; fourth, the 

 nervous system is derived from the mesoderm, — then 

 it is obvious that the general conclusions which we 

 are wont to consider to have been well established by 

 embryological research are erroneous, although they 

 rest upon a vast body of evidence. One would sup- 

 pose that no attempt to set this evidence aside would 

 be made, except after the most unquestionable 

 determination of new facts. Now, Metschnikoff 's 

 researches leave every one of the processes involved 

 in his novel views in absolute darkness; for he has 

 not, for the most part, observed them at all. His 

 surprising deductions are based upon a failure to 

 ascertain what are the actual processes, and seem to 

 the reporter invalid. The value of the real obser- 

 vations is, of course, unaffected by the speculative 

 portions of the essay. — {Zeitsch. loiss. zool., xxxviii. 

 331.) c. s. M. [34:9 



Insects. 



Epidermal glands of caterpillars and Mala- 

 chius. — The following are the principal results ob- 

 tained by Stan. Klemensiewicz. 1°. The eighth and 

 ninth segments of the larvae of Liparis, Leucoma, 

 Orgyia, and Porthesia auriflua, have each a little pro- 

 tuberance on the median dorsal line, with the open- 

 ing of a gland at the summit. The secretion is clear 

 and odorless. The skin is invaginated at the top 

 of the papilla to form a pendent sack, at the base of 

 which are inserted two muscles running obliquely 

 backwards ; and there also open two glands by a com- 

 mon duct. The external surface of the glands is 

 smooth, but in their interior each gland-cell forms 

 a separate bulging mass: the appearance thus pre- 

 sented is singular. The lumen of the duct is very 

 small; its thick walls are formed by two large cells, 

 much like those of the gland proper. In Leucoma 

 salicis there are quite similar glands on the fourth 

 and fifth segments. 2°. The exsertile horns of Pa- 

 pilio Machaon, larva, are described. They are really 

 developments of the tegument: the epidermal cells 

 of their walls are large, and contain numerous rod- 



haped bodies; but the cells at the base of the 

 horns are much smaller, and glandular (their secre- 

 tion being probably discharged through pores of the 

 adjacent cuticula). It may be assumed, that the 



odorous secretion accumulates in the invaginated 

 horns, and is freed by their exsertion. 3°. The cat- 

 erpillar of Harpyia vinula has a gland in the first seg- 

 ment, opening ventrally. The gland is flasly-shaped, 

 the neck acting as duct, and opening into a large 

 transverse fissure; the body of the flask is the gland 

 proper, and is lined by polygonal epithelial cells, with 

 irregularly shaped nuclei ; the epithelium rests upon a 

 thin tunica propria. 4°. A similar organ to the last 

 mentioned was described in A'anessa larvae, by Ro- 

 genhofer ( Verh. zool.-bol. ges. Wien, xii. 1227) : it is an 

 invagination of the skin on the ventral side of the 

 first segment; its cuticula is thin, and forms numerous 

 little cups, under each of which is a thin epithelial 

 cell. 5°. The orange-colored fleshy warts on the 

 sides of the thorax and abdomen of Malachius are 

 also glandular. The epidermis presents no special 

 features in the warts, except that it bears scattered 

 unicellular glands of the form typical for insects; 

 they ai'e flask-shaped, with a coiled cuticular duct 

 in their interior, the duct being continuous with a 

 pore-canal through the general cuticula of the wart. 

 In the lower and larger end of each cell, lies the round 

 nucleus. — {Verh. zool.-bot. yes. lI'ffiH, xxxii. 409.) 

 C. S. M. [350 



ANTHROPOLOGY. 



Prehistoric copper. — Professor J. D. Butler con- 

 fidently asserts that the Wisconsin state historical 

 society's collection contains more American aborigi- 

 nal copper implements than he has been able to hear 

 of in all other cabinets whatever. One axe weighs 

 four pounds twelve ounces and a quarter, and is the 

 heaviest article of wrought copper as yet brought to 

 light. Fourteen new implements have lately been 

 added, some of them unique in form, or size, or in 

 the location from which they were derived. More 

 than fifty coppers have come to the cabinet from 

 Washington county alone. This fact is doubtless 

 due to Mr. Perkins's persistent search in that locality. 

 — {yVisc. hist, coll., ix. 91.) J. w. P. [351 



Aztalau. — The largest and most elaborate aborigi- 

 nal monument in Wisconsin is Aztalan, fifty miles 

 east of Madison. It was first discovered by Timothy 

 Johnson in 1830, and described by Nathaniel F. Hyer 

 in the Milwaukee advertiser, January, 1837. Mr. 

 Stephen Taylor gave an illustrated account of it ia 

 Silliviaii's journal in 1843; and the place was first 

 accurately surveyed and plotted by Dr. Lapham, in 

 1850, whose description and drawings were published 

 in 1855, in the Smithsonian contributions to knowl- 

 edge. "This strange monument," says Prof. But- 

 ler, " was styled Aztalan by Mr. Hyer, inasmuch 

 as it seemed to him a structure worthy of the Aztecs." 

 Upon this point Mr. Peet says, " The name Aztalan 

 was derived from a tradition, whicli was said to be 

 common among the Indians, that a people p.artially 

 civilized built here a city, and a hundred years after- 

 ward, becoming dissatisfied, proceeded south to Mex- 

 ico." There is no reason to "suppose that the Aztecs, 

 or any other Mexican people, were in any way con- 

 nected with it. >Iuch curiosity has been excited with 

 reference to the Aztalan bricks, which are shapeless 



