NATURAL HISTORY MISCELLANY. 723 
SENSITIVE SURFACE IN Movuse’s Ear. — We learn from the “ Quar- 
terly Journal of Microscopy ” that Dr. Schobl, who lately published 
aremarkable paper on the wing of the bat, has made similar re- 
searches on the ear of the white mouse, with very interesting and 
surprising results. The first thing which attracted his attention 
was the immense richness of the ear in nerves. Even the bat’s 
wing is but poorly supplied in comparison. Calculating from the 
average size of the ear of a common mouse, he found that there 
are on the average 3,000 nerve terminations on each of its surfaces, 
making 6,000 on each ear, or 12,000 altogether. The function of 
this elaborate arrangement would seem to be, like that in the wing 
of the bat, to supply by means of a very refined sense of touch 
the want of vision to these subterranean animals. . 
DEVELOPMENT OF Nocrituca.—All that has been known as to 
the mode of development of this minute Fig. 121. 
animal (Fig. 121), that causes a great pn = 
part of the phosphorescence of our seas, 
is that they multiply by division and in- 
ternal budding. Prof. Cienkowski, as 
the “ Quarterly Journal of Microscopy” 
states, has traced the ‘ormation of 
spores like those of some fungi, and seen 
them swimming around like the zoospores of sea weeds. He has 
also observed the mode of sexual union of these animals. 
RELATIONS OF EMBRYOLOGY TO PATHOLOGY.— Dr. Dohrn reviews 
in the “ Academy” some observations made in the Pathological 
Institute of Jena by Prof. W. Müller, and published in the ‘‘ Jena 
Zeitschrift.” The papers contain a singular mixture of embryology 
and pathology, and embrace a field of comparative embryology that 
has hitherto remained wholly uncultivated. In regard to the chorda 
dorsalis, Miiller shows that it plays a secondary part in the forma- 
tion of the skeleton of Vertebrates. We can very well imagine 
animals, Dohrn says, with bones in their interior, and even ani- 
mals with a vertebrate skeleton, which present no traces of a 
chorda, while on the other hand we may meet with the chorda in 
invertebrate animals, such as the larvee of AARS, which devel- 
op no trace of an internal skeleton. 
Miiller’s papers also show ihat a new era in pathological anat- 
AMER. NATURALIST, VOL. V- 46 
