ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 



371 



The author suggests that the haematopoetic centres use up the disengaged 

 mononuclears to satisfy the immediate defensive needs of the organism, 

 and do not at the outset proceed to a reparatory proliferation. J. E. 



The Leucocytes in Experimental Spirochetosis ictohaemorrhagica 

 in the Guinea-pig.— J. Bablet {G.R. Soc. Biol., l'J18, 81, 300-3). 

 Leucocytosis ranging from 7,600 to 35,000 per c.cm. against a normal 

 of 3,500 {sic) is a constant feature, and reaches a maximum in five 

 days, associated with the disappearance of mononuclear cells and the 

 early appearance of abnormal cells, particularly myelocytes ; most 

 marked during the first three days. The following table gives the 

 means of numerous counts : — 



After Inoculation. 



The myelocytosis takes place at the expense of the polymorpho- 

 nuclear cells, which, however, regain their normal fiijure as the myelo- 

 cytes diminish. At first polymorphs with multilobular nuclei are the 

 rule, and single or bi-lobed cells the exception ; after the fourth day this 

 formula is reversed. J. E. 



Tuuicata* 



Philippine Ascidians. — "Willard G. Van Name {Bull. U.S. Nat. 

 Museum, 1918, 100, 49-174, 11 pi., 115 figs.). The Ascidian fauna of 

 the Philippines is an integral part of thit of the Malay region, not a 

 distinct and separate one. It is very abundant and varied in the 

 southern part, especially in the Sulu Archipelago. To the north, among 

 the islands, it diminishes both in abundance and variety. It is distinctly 

 a tropical fauna. Its relations to that of the temperate portions of the 

 Australian coast are much closer than to those of the less-distant regions 

 on the north, since on account of the warm currents many tropical 

 Malayan forms range southward alnng the east coast of Australia and 

 even through Bass Strait. Forty-six species are dealt with, including 

 two new genera and eight new species. J. A. T. 



Vascular System of Ascidian. - Selig Hecht {Amer. Journ. 

 Physiol., 1918,45, 157-87, 6 figs.) finds that the blood of Axcidia atra 

 is colourless and transparent ; that it flows throuiih the body under an 

 appreciable pressure ; that the blood plasma is isotonic with sea-water ; 

 and that the blood has an acid reacti(ni, tlie aciditv being resident in 

 the green corpuscles and not in the plasma. There are at least two 

 kinds of cells in the blood — pigmented and unpigmented. Of the 

 pigmented cells, the green are distributed all over the body, the orange 



2 c 2 



