Apkll 20, 1883.] 



SCIENCE. 



305 



tion that determines the position of the Delaware 

 Gap is regarded as warping or gentle transverse fold- 

 ing, rather than as a fault, as it has generally been 

 considered (p. 338). The map of glacial striae includ- 

 ed in this vohrme is constructed by Professor Lesley, 

 from Ml-. White's observations. It shows a general 

 trend uf striae S. 20 to 30° W., but with significant 

 deflections on approaching Kittatinny and Pocono 

 Mountains. A perched bowlder was found on the 

 top of High Knob, 2,010 feet above tide, and glacial 

 scratches were observed on Pocono Mountain at an 

 elevation of 2,1.50 feet. W. M. Davis. 



The original article is published in the Zooloy. 

 anzeiger, no. 132. Charles S. Minot. 



AN APPARENTLY NEW ANIMAL TYPE. 



Pkof. F. E. Schulze, who already ranks so high 

 among zoologists, has now another claim to distinc- 

 tion, through the discovery of an animal quite dififer- 

 ent from any tiling hitherto known. 



The animal was observed in the salt-water aquaria 

 of the zoological institute at Graz. It is a thin plate, 

 about 0.02 mm. thick, and only a few millimetres in 

 diameter. It constantly changes its form. It is trans- 

 lucent, and grayish white in color. At rest it is 

 rounded in outline, but may draw itself out into a 

 long thread, which may so curl and twist, that it 

 recalls a Persian or a Turkish letter. The move- 

 ments are usually so slow as to be barely perceptible, 

 as the animals creep along upon their under surfaces. 



Microscopic examination shows tliat the whole siu-- 

 face of the body is ciliated. Close under the upper 

 surface is a layer of highly refractile balls from .5 to 8/^ 

 in diameter, and distributed pretty evenly. Besides 

 these, there are other balls nearer the under surface, 

 which seem to be essentially different from those first 

 mentioned. There is no indication of internal or- 

 gans, nor of only bilateral or radiate symmetry: the 

 organism is uniaxial. Schulze names it the ciliated 

 plate, Trichoplax, with the specific name adhaerens, 

 because it clings so closely to the surface on which 

 it is moving. - 



Such an "organism one would expect to find re- 

 lated to the protozoa; far from it, for two different 

 epithelial layers of cells form its upper and lower 

 surfaces, and contain between them a fully developed 

 layer of connective tissue. The upper epithelium is 

 composed of large, flattened, polygonal cells: the 

 lower epithelium, on the contrary, is composed of 

 cylinder-cells, whose outer ends form a mosaic of 

 small polygons, but whose inner ends terminate in 

 processes that are lost in the connective tissue. This 

 last, forming the middle layer of the body, consists 

 of spindle-shaped and branching nucleated cells, 

 which are probably contractile, and are embedded in 

 a hyaline basal substance. The balls above mentioned 

 are contained in large cells. There are, then, three 

 layers, which from their relations would naturally be 

 compared with the ectoderm, mesoderm, and endo- 

 derm of other metazoa; but the justification of this 

 comparison must await a knowledge of the develop- 

 ment of the organism. 



Professor Schulze speculates as to the relationship 

 of this creature, but finds it impossible to assign 

 It to any known class. Although it has been watched 

 for a year, no sign of metamorphosis or of reproduc- 

 tion has been observed ; but Schulze thinks it possible 

 that it may have multiplied in the autumn by divis- 

 ion. 



It seems to me that the animal bears a strong re- 

 semblance to a sponge larva. The surmise that it is 

 the young of a porifer may be a useful hint for the 

 further study of this singular form. 



THE COLOR-PREFERENCES OF THE 

 HIVE-BEE. 



Dr. Hermann Mulleb, who does not accept the 

 results of Sir John Lubbock's studies of this subject 

 as very conclusive, has himself made a considerable 

 number of observations in the same line (Kosmos 

 for .Jan.). Though too few to serve as a basis for 

 very broad generalization, they give, so far as they 

 go, a strong degree of proof to several points pre- 

 viously theoretical. 



The colors experimented upon were not artificial, 

 but actual floral colors, prepared for use by gumming 

 fresh petals between two ordinary microscope-slides, 

 care being taken that no protruding parts were left, 

 and that the margin was sealed with gum-water, to 

 prevent the possibility of any odor from the petals 

 influencing the bees in their choice. 



The bees to be observed were at first accustomed to 

 visit uncolored slides, smeared with honey, exposed 

 close by their hive, and gradually removed, in the 

 course of several days, to a distance of twenty-six 

 metres, where they were replaced by two slides of 

 the colors to be compared, similarly smeared, and 

 placed one decimetre apart. Each bee was marked 

 on its back with an oil-color, by which it was recog- 

 nized on its different visits. It was found later, that 

 bees from distant hives, if caught on flowers a few 

 steps from the place of observation, and transferred 

 to the honeyed slides under a tumbler that had been 

 sweetened in the same way,usually returned regularly. 



In the different observations a number of marked 

 bees were employed, both as a means of economizing 

 time, and to compensate for the somewhat different 

 preferences of individual insects. To eliminate the 

 influence of location, the positions of the slides under 

 observation were changed from time to time. 



The general results reached are as follows : — 



Leaf-green is less attractive to bees than the colors 

 usually found in flowers adapted to pollination by 

 them. 



The colors of these, which may be conveniently 

 called bee-flowers, are, without exception, preferred 

 to fulgent colors, like the yellow of buttercups and 

 the scarlet of some poppies, which usually occur in 

 flowers open to a mixed circle of visitors, ur adapted 

 to humming-birds. The extent of their choice in 

 each case may be seen from the annexed table; the 

 figures indicating the relative number of visits, on a 

 basis of 1,000 to each bee-flower color. (Table I.) 



Fulgent colors are less attractive to bees than the 

 neutral tint which precedes them in the development 

 of the flower. 



Bright yellow is less distasteful than other brilliant 

 colors, but it is least acceptable of the colors found 

 in bee-flowers. (Table II.) 



Yellowish white and white are at least as attractive 

 to Apis as many shades of purple, but less so than 

 blue and violet. (Table IIL ) 



Blue is preferred to the red of bee-flowers, or is at 

 least equally acceptable, in the shades tested. Pure 

 deep blue is even more attractive than violet. 

 (Table IV.) 



With the exception of blue, violet is more attractive 

 than other colors experimented with. (Table V.) 



Red, in the shades found in bee-flowers, constantly 

 surpasses only yellow in its attractiveness for the 

 hive-bee. It is equalled or surpassed by all other 

 colors used for comparison. (Table VI.) 



