716 SCIENCE. 
attention, finally, among the schizopods, to Gnatau- 
phausia, of large size, and of a scarlet color. The 
lower crustaceans, Amphipoda and Isopoda, were 
found in large numbers; but a study of them is 
much less interesting than that of the forms of 
which we have just spoken. Thespecies of Nymphon 
is abundant at great depths; and a giant form, whose 
stomach extends to the end of its claws, Colossen- 
deis titan, was taken at four thousand metres. 
With crustaceans, as with fishes, it is very inter- 
esting to inquire whether the circumstances sur- 
rounding them cause modifications and adaptations 
in their organisms. The changes in the tissues are 
often noticeable in the structure of the carapace and 
muscles. I have already called attention to Penta- 
cheles, Polycheles, and Willemoesia, whose tissues 
are so transparent as to allow the viscera to be seen; 
and the flesh is tender, and lacking flavor. The 
exterior colors are either a bright red, a rose-white, 
or a pure white. The macruran Crustacea are spe- 
cially noticeable for their brilliant colors: and one 
cannot restrain a feeling of admiration for Aristes, 
of a carmine color; Notostomus, of a pure, deep red; 
and Pasiphae, spotted red and white. At very great 
depths, rose-white or pure white are the only tints 
observed. 
With the fishes, as we have seen, the visual organs 
are always well developed, at whatever depth these 
animals are taken. It is not so with the Crusta- 
cea, several species of quite different groups having 
experienced atrophy, and sometimes a complete dis- 
appearance of the eyes. It is, however, a very sin- 
gular fact, that some species in the same genus are 
blind, and others are not. Thus Ethusa granulata, 
living in the German ocean, between two hundred 
and thirteen hundred metres, is blind; while Ethusa 
alba, taken in the Atlantic, at five thousand metres, 
is not blind. The disappearance of the eyes seems 
to be gradual, and to be related to the depth at which 
the animal lives. The cornea first disappears, the 
ocular stalk remaining, and being movable. Then 
these parts become fixed, and, losing their charac- 
ters, are changed into spines. Thus, says Norman, 
‘“Hthusa granulata, dredged between one hundred 
and ten and three hundred and seventy fathoms, has 
two remarkable ocular stalks, smooth and rounded 
at the extremity, where ordinarily the eyes are 
placed. With the specimens from the north, living 
at a depth of from five hundred and forty-two to 
seven hundred and five fathoms, the ocular stalks 
are no longer movable: they become fixed in the 
sockets, and their function is changed. Their dimen- 
sions are much enlarged; they approach their foun- 
dation; and, instead of being rounded, they end ina 
very firm rostrum. No longer serving as eyes, they 
serve as rostra.’”’ We have on exhibition one blind 
species, Galathodes Antonii (fig. 1), taken on the 
Talisman; and near this strange form, whose eyes 
are replaced by sharp spines, may be seen Penta- 
cheles, Polycheles, Willemoesia, and Cymonomus, 
whose eyes are more or less changed. 
Crustaceans of great depths emit phosphorescence. 
The light is shed, sometimes by the whole surface 
[Vou. ILI., No. 71. 
of the body, and sometimes, as with Aristes, in a 
special manner, by the eyes themselves. With some 
of them it seems as if there were, in certain parts of 
the body, organs arranged for the production of this 
light, —a fact which recalls what was said about 
fishes. Thus in Acantephyra pellucida, a new species, 
the claws are furnished with phosphorescent bands. 
The organs of touch are considerably developed, the 
most remarkable example of which is found in the 
long antennae of Aristes. With certain crustaceans, 
as in Benthesisymnus, the last pair of claws assume 
the character of antennae, and have the same func- 
tion, probably, as these organs. 
THE WOBURN ROTATION EXPERI- 
MENTS. 
For the past six years some very interesting 
field-experiments have been in progress at Woburn, 
Eng., under the conduct of Dr. Voelcker, chemist of 
the Royal agricultural society. A portion of these 
experiments are upon the continuous growth of wheat 
and barley on the same land, and closely resemble 
the celebrated Rothamsted experiments, differing 
from them in being made upon light land. Other of 
the experiments are rotation experiments, and are 
designed to test the comparative agricultural value 
of artificial fertilizers, and of barnyard-manure made 
from different feeding-stuffs. These experiments are 
to be continued for a series of years; but a brief de- 
scription of their plan, and a statement of the results 
obtained up to the present time, may not be without 
interest. 
The rotation is an ordinary four-course rotation; 
viz., roots, barley, grass, and wheat. Sixteen acres are 
under experiment; so that, in any given year, four 
acres are covered by each crop, while, in the course 
of four years, each plot of four acres bears succes- 
sively the crops above enumerated. The following 
table shows at one view the crops thus far carried by 
each plot: — 
Date. Plot 1. | Plot 2. | Plot 3. | Plot 4. 
US “Gdeoko, & oo Fo TMeAgE Roots - - 
STS) f5 = oe ee nee) Wheaton |pearley, Grass Roots 
1379. oe eee yl OOts Grass Wheat | Barley 
USSON se | reer oanley, Wheat Roots Grass: 
SSI. ee ee ass Roots Barley Wheat © 
S82. seen eV Aneat Barley Grass Roots 
FBBB. sie) e cere yous | ROOtS Grass Wheat | Barley 
Each plot of four acres is subdivided into four 
one-acre sections, and these are fertilized in different 
ways. As each of the four plots is treated exactly 
alike in successive years, it will suffice to follow one 
plot through the four years, in order to understand 
how each section of it is fertilized. Plot No. 1 was 
in grass in 1877, the grass being a mixture of clover 
and rye-grass. Sheep were pastured on each of the 
four sections of this plot sufficient to consume the © 
grass. To the sheep on the first section were given _ 
728 pounds of decorticated cottonseed-meal, and i 
