ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
575 
way the centre. In either case the nucleolus is seen to be an element 
of the highest importance in the biology of the cell. 
Division of Pigment-cells and Capillary Wall-cells. * * * § — Prof. W. 
Flemming gives an account of some observations which, like the budding 
of Protista and the division of leucocytes, show that a cell-body may be 
divided by forces which need not in any way correspond with those 
which are active in the division of the nucleus. 
B. mVERTEBRATA. 
Functions of Central Nervous System of Invertebrates.! — Prof. J. 
Steiner has a short account of his experiments on the central nervous 
system of various Invertebrates. He comes to the conclusion that, while 
the Arthropoda have a true brain like that of Vertebrates and repre- 
sented by the dorsal oesophageal ganglion, no others of the Invertebrates 
have a brain. In the Mollusca and Annelida this dorsal ganglion is, 
according to our present knowledge, only a sensory centre ; in the 
unsegmented worms (of which Distoma hepaticum is taken as the type) 
the dorsal ganglion forms the whole of the central nervous system ; on 
the one hand, it is the primary centre of the locomotor organs, but at 
the same time it is also a sensory centre. Further investigations must 
show whether other distinct types of nervous systems are exhibited by 
the Echinodermata and Ccelenterata. 
Animal Parasites of Sheep. ! — Dr. Cooper Curtice has published a 
report on the parasites of the sheep, which ought to be of particular 
interest and value. Twenty-six species of animal parasites are recorded, 
six of which are Cestodes, three Trematodes, and ten Nematodes, the 
rest being Arthropods of various groups ; nine of all these are the most 
destructive. A new species is described in the form of the nematode 
CEsophagostoma columbianum , which seems to be the cause of a hitherto 
undescribed disease which is characterized by tumours in the upper part 
of the large intestine ; one great misfortune of this disease is the 
disturbance to the business of the sausage-makers, who are compelled to 
import the greater part of the covering material which is used in their 
business. The origin of this pest, which does not seem to have been 
brought over to America from the Old World, is still obscure, and the 
complete life-history of the species has still to be made out. 
German Names for Porifera, Ccelenterata, Echinoderms, and 
Worms.§ — As English-speaking naturalists are very often at a loss to 
know what is meant by the German name of an animal or a group — 
e. g. by Kieferwiirmer and Kohrenkieferwiirmer, or by Wiirzelschopf- 
schwamme, we may call attention to a useful list lately published by 
Dr. E. v. Marenzeller. 
* Arch. f. Mikr. Anal., xxxv. (1890) pp. 275-86 (1 pi.). 
f SB. lv. Preuss. Akad. Wiss., 1890, pp. 39-49. 
j 4 The Animal Parasites of Sheep.’ U.S. Department of Agriculture, Washing- 
ton, 1890, 8 vo, 222 pp. and 36 pis. 
§ Abh. Zool.-Bot. Gesell., xl. (1890) pp. 177-84. 
