ZOOLOGY AND BOTANY, MIOKOSCOPY, ETC. 
311 
lymphocytes, and are able to swallow the former (leucocytes), and to 
destroy and digest them. Within the interior of both, micro-organisms 
are rapidly destroyed, and these last are never found living free 
between the cells or in the blood-vessels and lymphatics. The destruction 
of micro-organisms in the normal lymphoid tissues of the alimentary 
tract resembles in all particulars the destructive process which follows 
the inoculation of pathogenic organisms into resistent animals. 
Histology of Striped Muscle.* — Mr. C. F. Marshall gives an 
account of his further f observations on the histology of striped muscle. 
He finds that the transverse portions of the network of the striped 
muscle-fibre are directly connected with the muscle-corpuscles. The 
nerve-ending appears to be connected with the muscle-network, and 
chiefly with its longitudinal bars. The development of the network 
takes place at a very early stage in the development of the fibre and is, 
from the first, developed in its permanent form. It developes first at 
the surface and grows centripetally, and it does not appear to be con- 
nected with the muscle-corpuscles till the fibre is fully developed. 
Each muscle-fibre appears to be developed from a single cell, and not 
by a coalescence of cells. Dytiscus, the Dragon-fly, and the Crayfish were 
used for investigation, while the development of the network was studied 
in embryos of the trout and rat. 
y. General. 
Classification of the Metazoa.J — Prof. E. Haeckel, at the conclu- 
sion of his report on the Deep-sea Keratosa, gives a synopsis of the 
Metazoa which differs somewhat from most of the classifications in 
vogue in this country. 
A. First Main Branch. 
CGELENTERIA. 
Phylum I. Gastr^ssada. 
Classes : 1. Physemaria ; 2. Cyemaria (Orthonectidee, Dicyemidaa). 
Phylum II. Spongi.® (Porifera). 
Classes : 1. Malthospongiae ; 2. SilicispongiaB ; 3. Calcispongise ; or, 
perhaps, better : 1. Protospongiae (Tubulosae) ; 2. Metaspongise 
(Vesiculosae). 
Phylum III. Cnidaria (Aoaleph^). 
III. a. Subphylum 1. Hydrozoa. 
Classes : 1. Hydropolypi ; 2. Hydromedusae ; 3. Siphonophora. 
III. h. Subphylum 2. Scyphozoa. 
Classes : 4. Scyphopolypi ; 5. Anthozoa ; 6. Scyphomedusae. 
* Quart. Journ. Micr. Sci., xxxi. (1890) pp. 65-82 (1 pi.). 
t See this Journal, 1887, p. 935. 
X Keports of the Voyage of H.M.S. ‘Challenger,’ xxxi.. Part Ixxxii. (1889) 
pp. 90-2. 
