350 
8UMHARY OF CURRENT RESEARCHES RELATING TO 
Natural History in La Plata.* * * § — Mr. W. H. Hudson’s book, which 
is not so strictly limited to the Vertebrata as are many works written by 
those who are best known as ornithologists, is one of the most interest- 
ing books that has been published for several years. No lover of 
Natural History should fail to read it. 
Comparative Pathology of Inflammation.! — Prof. E. Ray Lankes- 
ter has an appreciative review of Prof. MetschnikofFs latest work J in 
which he gives a “ clear account of his phagocyte theory, tracing the 
significance of amoeboid cells or phagocytes from the Protozoa upwards 
through various groups of animals to the higher Vertebrates.” Inflam- 
mation is shown to be essentially a reaction of the phagocytes contained 
in animal bodies to the presence of injured tissue or intrusive particles. 
Prof. Lankester thinks the work will establish on a solid basis the 
doctrine of phagocytes, which he ranks with Virchow’s cellular patho- 
logy and Pasteur’s doctrine of the bacterial origin of fermentations and 
infective diseases. It is urged that the study of the lower animals is 
capable of furnishing us with the key, as it were, to those complicated 
pathological phenomena which are most interesting for medical science. 
Examples of parasitic infection among Infusoria are described, and 
“ chemiotaxis ” is shown to be characteristic of amoeboid protoplasm. 
The reaction of mesodermic phagocytes of various Metazoa to foreign 
matters is described, numerous instances are given of bacterial and 
fungus diseases in Arthropoda, and the action of phagocytes in com- 
bating the intrusive parasites by ingulfing and digesting them is 
demonstrated. A detailed study is made of the leucocytes of the blood 
and lymph of Vertebrates, which are distinguished as lymphocytes, 
uninuclear, eosinophil, and neutrophil or multinuclear leucocytes. 
B. INVERTEBRATA. 
Phagocyte-organs of Invertebrates.§ — M. L. Cuenot has made 
experiments on phagocytosis in some Invertebrates. He injected into 
the coelom of vigorous and well-fed animals a varying quantity of fresh 
defibrinated mammalian blood. The red blood-corpuscles are absorbed 
by the phagocyte-organs when such exist, and give them an intense 
colour, which reveals them at once, when the animal is dissected. In 
Pulmonate Gastropods these red corpuscles are chiefly found in the 
connective tissue filled with large vesicular cells (cells of Leydig) ; 
these cells digest the foreign corpuscles. In the Crayfish the branchial 
glands become intensely red after the injection. In the Insects 
examined no phagocyte-organs were found ; the injected corpuscles 
remain in the blood, and the animals die in a few days. Though 
Asterias rubens and Echinus miliaris have no phagocyte-organs, these 
animals are capable of resisting the injection of considerable quantities 
of blood, for the amoebocy tes seize these corpuscles and free the organism 
of them. 
* ‘ The Naturalist in La Plata,’ London, 8vo, 1892, 383 pp., illustrated. 
t Nature, xlv. (1892) pp. 505-6. 
j * Lemons sur la Pathologic compare'ede l’lnflammation,’ Paris, G. Masson, 1892. 
§ Arch. Zool. Expcr. et Gen., x. (1892) pp. ix.-xi. 
