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from a child’s mouth, which was evidently the same species. It having 
been in a child’s mouth is probably to be explained by supposing that the 
-child had eaten an infected apple. 
Do Vertebrate Animals come from Amphioxus ? — “ The Academy ” states 
(May 29) that the view of most recent zoologists that the origin of the ver- 
tebrated subkingdom is to be traced through Amphioxus from the Ascidians, 
is supported by M. Ussow in the last published part of his 11 Zoologisch- 
embryologische Untersuchungen ” (“Archiv fur Naturgeschichte,” 1875, pp. 
1-18; “Ann. Mag. Nat. Hist.” xv., pp. 321-333). He considers the Tunicata 
to be quite distinct from the Mollusca both in their embryonal development 
and in their type of structure. Their closest affinities are with the Bryozoa: 
hut adherence is given to Schmidt’s classification, in which they form a 
•distinct class of Proto-vertebrata. Dr. Anton Dohrn advocates a contrary 
opinion in a memoir entitled “ Der Ursprung der Wirbelthiere, und das 
Princip des Functionswechsels (Leipzig, 1875).” His embryological investi- 
gations lead him to seek for the probable ancestors of the higher animals 
among the Arthropoda rather than the Tunicata, and to revert to the views 
of the elder St. Hilaire who described insects as vertebrates which run 
with their back downwards, rather than to those of Kowalevsky and his 
followers who trace the line through the Ascidians and the lancelet. So 
far from being the representative of the original vertebrates, the Amphioxus 
is regarded by Dr. Dohrn as a degenerate descendant of the cyclostomous 
fish, and the so-called larvre of the Ascidians are the result of a still longer 
continued process of degradation. With regard to the principle of change 
of function, the general rule is laid down that the function of an organ is 
made up of a principal and other secondary components ; if the former de- 
crease in force and the latter increase, the whole function is changed, and 
the organ itself is altered in consequence. 
The Spiders of the Mammoth Cave , U.S.A., have been recently examined 
by Mr. A. S. Packard, Jun., who states (“American Naturalist’s Magazine”) 
“ that they occurred more abundantly in all the caves than we expected. 
The individual abundance was greater in the smaller caverns, especially 
the Weyer’s caves, than any others. In the Mammoth Cave the Anthrobia 
occurred under stones in dry but not the driest places, on the bottom, at 
different points in the cave. Sometimes two or three cocoons would be 
found under a stone as large as a man’s head. The cocoons were orbicular, 
flattened, an eighth of an inch in diameter, and formed of fine silk, and con- 
tained from two to five eggs. They occurred with eggs in which the blasto- 
dermic cells were just formed, April 25. The eggs were few in number, 
and seemed large for so small a spider, being inch in diameter. The 
chorion is very thin, and finely speckled. The blastodermic cells seemed 
very large, the largest measuring nearly inch in diameter. They were 
round, not closely packed, and showing no indications of being polygonal. 
They all had a dark, very distinct nucleus. I was unable to trace the de- 
velopment of the young, and ascertain if the embryos are provided with 
rudimentary eyes. Two young Anthrobice hatched out May 3 in my room. 
The whole body, including the legs, is snow white, with the legs much 
shorter than in the adult. The adult in life is white, tinged with a very 
faint flesh colour, with the abdomen reddish ; in some specimens the abdo- 
