720 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
between tlie lung of a Reptile and that of a higher Vertebrate. Of the 
prolongations given off from the bladder one is of special interest as it 
descends along the intestine and unites with its fellow of the opposite 
side to form an enormous unpaired abdominal bladder. 
In Galathea strigosa the gland is deeply divided into several lobes, 
which are themselves broken up into several secondary lobules ; the 
saccule has ramifications which are much more developed than those of 
Pagurus ; the antennary gland has a structure very similar to that 
of Galathea. The bladder of the Brachyura is remarkable for its 
great size ; in Platycarcinus pagurus, Carcinus msenas, Xantho floridus , 
Portunus puber , and others, there is an enormous hind-bladder which 
communicates with the rest by a narrow tunnel hollowed under the 
mobile insertion of the adductor of the mandible. In front there is 
a large suprastomachal paired lobe. 
Metallic'Brilliancy of Sapphirinidae.* — Dr. H. Ambronn has inves- 
tigated the causes of the metallic brilliancy of the Sapphirinidae, on 
which Gegenbaur, Claus, and Haeckel have already written. He came 
to the conclusion that he had to do with the interference colours that 
appear in very thin layers. There appears to be a layer in which are 
closely set uniaxal anisotropic structures which are perhaps true 
crystals. The dimensions of these vary in various species ; in Sapphi- 
rina fulgens they have a transverse diameter of about 0 • 8-1 /x, while the 
long diameter is 1 * 3 /x ; in a form allied to Sapphirina pachygaster the 
dimensions are somewhat greater. But as these sizes are too great it is 
necessary to suppose that between the chitinous investment and the 
layer of prisms there is a layer of slight refractive power which cannot 
bo morphologically distinguished ; the layer of prisms would then 
increase the intensity of the colours by acting as a strongly reflecting 
layer. Observations show that the colours are not the spectral colours 
of a grating. 
Minute Structure of Eye of Arcturus.j — Mr. F. E. Beddard gives 
descriptions of the minute structure of the eye in some shallow-water 
and deep-sea species of this genus of Isopods. He finds that all the 
shallow-water species examined have lenses which are perfectly clear and 
transparent and are characteristically pear-shaped. On the other hand, 
all those species which appear to have a partly opaque lens are deep- 
sea forms, and in some there is a reduction in the size and an alteration 
in the shape of the lens which may be thought to impair its perfection 
as an organ for the passage of rays of light. Another point of consider- 
able importance in relation to the supposed degeneration of the eye is the 
smaller amount of pigment which is found in the eye of most of the 
deep-sea species that were examined by the author. 
Development of Amphipoda.J — In the fourth of her studies 
Madame Marie Rossiiskaya-Koschewnikowa describes the development of 
Sunamphitoe valida and Amphitoe picta. The former does not differ 
from other Amphipods in the mode of formation of its germinal layers 
* Mittheil. Zool. Stat. Neapel, ix. (1890) pp. 479-82. 
t Proc. Zool. Soc. Lond., 1890, pp. 365-75 (1 pi.). 
X Bull. Soc. Imp. Nat. Moscow, 1890, pp. 82-103 (2 pis.). 
