NATURAL HISTORY MISCELLANY. 441 
way, and in an equal mixture of fresh and salt water, afford very 
good objects for study.” i 
The embryology of scorpions was sketched out in a general way 
by the distinguished German embryologist Rathke. Metschnikoff 
extends these researches very greatly, and considers as the most 
important results of his studies the discovery that ‘‘in the embryo 
of the scorpions three embryonal membranes are developed, which, 
in many respects ‘are very strikingly similar to the Remackian em- 
bryonal membranes of the vertebrates.” 
A SOUTH American Brrp IN THE Unitrep Srares.— The speci- 
men of Erismatura Dominica, the gift of Mr. Thure Kumlien of 
Bussyville, Wisconsin, having been presented, Dr. Brewer called 
the attention of the Boston Society of Natural History to the 
interest attaching to this specimen. It is a South American bird, 
and this specimen is the second obtained in the United States. 
The first, a male, was shot at Lake Champlain, and was presented 
to the society by Dr. Samuel Cabot. This specimen, the second 
ever obtained north of Mexico, was shot at Rock River, Bussyville, 
Wisconsin, November, 1870. It is a female; its total length is 
fourteen inches; alar extent twenty and one-half inches. The 
tail consists of twenty very narrow feathers, of which the first is 
the shortest. The tail extends only three inches beyond the 
folded wings. Bill one and one-sixteenth inches from base to tip 
above; one and nine-sixteenths depth at base, and three-fourths 
of an inch wide. Wing with second primary longest; third and 
first, even. Iris, brown. 
Snap Eces.— When shad eggs are first impregnated they are 
very small, but after a short time they swell greatly and the water 
in the impregnating pan becomes about 10° colder. — A. S. COLLINS. 
[Can any one give us an explanation of this fact?— Eps. ] 
DISCOVERY OF THE ANIMAL OF THE SPONGIADA CONFIRMED. — 
Just a line to tell you what you will be glad to learn, viz., that I 
have confirmed all that Prof. James Clark of Boston, [now of the 
Kentucky University] has stated about the sponge-cell, and much 
more too. 
It is, after all, only what was published and illustrated in the 
+‘ Annals” in 1857. Indeed, I am astonished now at the accuracy 
and detail of that paper (“Ultimate Structure of Spongilla,” 
ete.), now all confirmed by an examination of a marine calcareous 
