ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 237 



Continuity of Cells and Amitotic Karyokinesis. — I. P. Munson 

 {Proc. Amer. Assoc. Aiiatomists, in Anat. Record, 1919, 16, 158-9). 

 Many cases are given of intercellular bridges connecting cells. Syncytia 

 are common. Cell membranes are often absent. A mode of cell- 

 division is described which is neither karyokinesis nor amitosis, but 

 rather a combination of the two. The nucleus divides by cleavage, 

 without forming a spindle. The centrosome divides, but the cell is not 

 divided. "The cell theory is at fault when it fails to recognize the 

 morphological continuity of protoplasm in many-celled organisms." 



J. A. T. 



Properties of Mesenchyme. — Vera Danchakoff {Proc. Amer. 

 Assoc. Anatomists, in Anat. Record, 1919, 16, 146-7). Only under 

 typical conditions does the greatest part of the embryonic mesenchyme 

 become the primordium for the interstitial tissue of various organs. In 

 experimental conditions much may proliferate into masses of granulo- 

 blastic tissue. Normally the interstitial connective tissue may retain 

 phagocytic and digestive power. This may be an important factor in 

 immunity. Tumour cells and erythrocytes may be surrounded and 

 digested. The phagocytic and digestive activity of a mesenchymal cell 

 is usually directed against dead particles, and possibly against weakened 

 cells of its own kind. But it may operate against other cells, and this 

 should be taken into account in interpreting the resistance of the 

 organism to heteroplastic grafting. J. A. T. 



Distribution of Clasmatocytes. — Claude S. Beck (Proc. Amer. 

 Assoc. Anatomists, in Anat. Record, 1919, 16, 143). Small pieces of 

 tissue from various organs were placed in neutral red Locke's solution. 

 In the subcutaneous tissue clasmatocytes are very abundant in the loose 

 reticulum of the connective- tissue cells. Similarly in the sub-mucosa of 

 stomach, intestine, oesophagus, in the sub-serous tissue. In the muscu- 

 lature of the gut they lie l)etween the muscle bundles. They are absent 

 from the endothelial lining of the gut and from the epidermis. They 

 are plentiful in the cornea, striped muscle, and pia arachnoid. There 

 are few in the amnion and in the sclera. There are few in the meso- 

 nephros, metanephros, and liver. They are abundant in the walls of the 

 Wolffian duct. There are very few in the liver. None were found in 

 optic lobes, retina, choroid. The method was unsatisfactory for the 

 examination of the spinal cord and parts of the brain. They seem 

 to be present in the choroid plexus and in the telencephalon medium. 



J. A. T. 



Structure of Clasmatocytes. — H. W. Vance {Proc. Amer. Assoc, 

 A^iatomists, in Anat. Record, 1919, 16, 166-7). Clasmatocytes are 

 abundant in cultures of subcutaneous tissue. Their most striking features 

 are the large central centrosphere, the large vacuoles, the excentric 

 nucleus. At the centre of the finely granular centrosphere is often seen 

 a single or double centriole. The periphery of the centrosphere is con- 

 tinued into the cytoplasmic framework, lying between the vacuoles 

 which otherwise fill up the peripheral regions of the cell. There are 

 often indications of radiations in the centrosphere which seem to 



