1878. | Recent Literature. 617 
we, on the other hand, are acquainted with the finer structure of 
the organs of hearing in the Orthoptera, and know that they have 
no such constituted brain-centres as the olfactory lobes 
Thirdly, Flogel draws attention to the wonderful and so little 
understood facts that in insects, where the lobes (“ bechers ” of 
Flogel, “lappen,” “ gestielte > körper,” etc., of Dietl) and the sub- 
stance around it (gerüst) constitute the greater part of the brain, 
there is indeed no connection of the nerve-fibres to be found with 
the remaining parts of the brain, and consequently also with the 
cesophageal commissures. The opinion that the ganglionic cells 
are in direct relation through fibres with the organs of the body 
is provisionally unfortuné itely contradicted. But where are the 
intermediate stations? he asks, 
Finally, the author claims that the essay indicates the outlidas 
of a future brain- -topography for insects, and shows that the single 
parts of the brain have their homologues in the different orders ° 
of insects ; consequently a ground- plan i in the organization is not 
to be mistaken, and thus a comparative anatomy of the brain of 
insects is outlined comparable with that of the vertebrates, as 
established by the researches of Stieda. 
Barrotis’ EMBRYOLOGY or Bryozoa.A—The author of this elab- 
orate and beautifully illustrated memoir is well-known for his able 
and thorough work on the development of the sponges and 
nemertean worms. A large number of typical forms of Polyzoa 
or Bryozoa, as the German and French call them, have been 
studied, and the different stages figured, including the genera 
Loxosoma, Pedicellina, and several genera of higher marine 
orms. We will give the general results of our author’s work 
condensed from the résumé général. A study of the different 
groups of E pa a MAR and i e PUP eters Polyzoa, shows that 
their development present s the same phenomena, characterized 
by the great regularity of the segmentation (orula) and giving 
rise to a dlastu/a, in which the advanced morula is composed of 
two distinct halves (oral and aboral) separated by a crown of cilia. 
Then the gastrula Far FIG. 2 
state is assumed and 
afterwards the me 
soderm arises. 
the moment otbirth, 
he embryo always 
withdraws the ab- 
oral end within the 
crown and thus as- 
aspect, but it can Fic. 1.—Blastula of eee at we Fic. 2.— 
undergo this > Gastrula ot ieee ame ; veginn € 
cess much more rapidly, previous to the appearance of the fur- 
1 Recherches su oe -yologie des Bryozoaires. Par J. BARROIS, Lille, 1877. 
4°, pp. 305, with 16 plat 
