ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
193 
damaged or wounded tissues. They are the agents by which resistance 
is offered to foreign bodies and microbes, while they also absorb sickly 
or degenerating tissues. It is not right to compare them to Amcebfe 
living in the organism, but rather to take Loewit’s view that they are 
floating unicellular glands. Being adapted to a more or less albuminous 
medium they are unable to live in water outside the body. The life- 
history of an amoebocyte is hard, if not impossible, to determine. 
The lymphatic glands, however variable in form, are always formed 
in the same way; there is a connective layer which incloses in its 
plasma a large number of nuclei ; these are surrounded by protoplasm, 
which is filled with refractive granules ; these cells become amoeboid 
and pass by diapedesis through the meshes of the connective tissue 
to fall into the blood. It is not always easy to find the lymphatic 
glands of any given animal, and in some cases this is doubtless due 
to the diffused arrangement which the gland takes on. 
Sometimes the lymphatic glands give rise to genital products, either 
directly or indirectly ; but this phenomenon is only well defined in the 
Echinodermata, and in the Trochozoa. 
Wandering Cells and Excretory Functions.*— Mr. H. E. Durham’s 
observations were chiefly made on Echinoderms, but Dytiscus marginalia 
and species of Unio and Anodonta were also examined. The author 
commences with a discussion of the fate of insoluble foreign particles ; 
the ingestion of Indian ink in normal salt solution into the abdomen of 
D. marginalis was followed by the appearance of one or more particles in 
many of the amoeboid blood-corpuscles. Then follows a process of en- 
capsulation, by means of which the particles are removed from the 
circulation. 
The next section of the paper deals with the diapedesis of leucocytes 
containing products of normal metabolism ; it seems probable that a 
process of excretion by means of wander-cells occurs in many animals, 
and that many of the “ mucous ” pigment and other cells described in 
epidermis may really be of the nature of wander-cells, whose onward 
progress has been stopped by the reagents of the histologist. One factor 
which may be of importance is the stimulus afforded by the contents of 
the cell. Inert granules, micro-organisms, pigment concretions and so 
on may cause the cell to wander further than it ordinarily would. 
Results of Indian Deep-sea Dredging.f — Prof. J. Wood-Mason and 
Dr. A. Alcock report that of the Echinodermata dredged from deep 
waters in the Indian Sea, the Asteroidea are represented by twenty-three 
species, fourteen of which appear to be undescribed ; Persiphonaster is a 
new genus allied to Plutonaster, and is represented by two new species. 
Bictyaster is a new genus of Echinasteridre, for 1). xenophilus sp. n. 
Three new species of Brisinga—B. insularum, B. bengalensis, and B. 
andamanica — are shortly defined. The new Echinoids are Prionecliinus 
Agassizii and Homolampas glauca. Nine genera of Holothurians and 
seven of Ophiuroids have been recognized but are not described. Of the 
Crinoids dredged one was a Eudiocrinus. Only three Cephalopoda were 
* Quart. Jouri). Micr. Sci., xxxiii. (1891) pp. 81-104 (1 p].). 
t Ann. and Mag. Nat. Hist., viii. (1891) pp. 427-52 (1 pi. and 6 woodcuts). 
