186 PBOGRESS OF MICROSCOPICAL SCIENCE. [fourmil! aS^^^^ 
without, however, penetrating too far into the substance inserted 
between the capsule and the internal club-shaped body. 
20. The funiculus, or stalk, of the Pacinian corpuscle consists 
essentially of a medullary nerve-fibre, enclosed in its own sheath, 
of a variable quantity of connective tissue with longitudinal fibres, 
and of one or two extremely small arteries. 
21. The function of the Pacinian corpuscles is essentially a 
special one, and different from that of other terminating nervous 
corpuscles. Its nature must be said to be unknown, j 
PKOaEESS OF MICKOSCOPIGAL SCIENCE. 
Tlie Development of the Floiver in Cruciferce. — A paper on this 
subject has been laid before the Academy of Sciences of Vienna by 
Herr Wretschko. He states that the young inflorescence of all these 
plants has the appearance of an extended and slightly-arched axis, 
from whose border flower-buds generally devoid of tracts may be 
seen differentiating. It is not uncommon to meet rudimentary tracts 
fixed to the buds, and of contemporaneous origin with them, which 
afterwards disappear without leaving any trace. Some species also 
have two rudimentary lateral leaves placed in front of the bud, and 
which seem never to be present when the tracts are. These leaves are 
earlier in origin than those of the calyx. This latter commences 
occasionally by the posterior sepal, but oftener by the anterior one; 
the median pair are very soon followed by the lateral pair. The four 
petals are developed simultaneously, and are soon followed by broad 
but small elevations, which are the first indications of the lateral 
stamens ; after which the receptacle becomes arched, and soon passes 
into a sort of square with rounded angles, on which appear four 
elevations (not in front of the petals), the first rough sketch, as it 
were, of the four long stamens. The progress of development shows 
nothing in favour of the theory of abortion, but it does not allow of 
our forming the conclusion that there is a common origin for each 
pair of long stamens, previous to that of the anterior and posterior 
sepals; consequently the theory of division of the median process 
which developes each pair of stamens is inadmissible. — Sitzungsber der 
Kaiser Akad. der Wissen in Wien. LVII Band. VII Heft. 
The Vitality of the Tissues in Sponges. — M. Leon Vaillant, following 
up the inquiries of Bowerbank, Lieberkiihn, and Oscar Schmidt, has 
been trying various experiments to determine the manner in which 
loss of substance is repaired in sponges. He has been trying to graft 
the sarcode in various ways. The species on which he operated espe- 
cially is one of the Corticatce of Schmidt, the Tethea lyncurium Lamarck, 
whose histology and regular form he considers more suited to the 
nature of the research than the species of Halichondria, employed by 
Dr. Bowerbank. The objections to it are — (1) that it does not live 
