582 



SCIENCE. 



[N. S. Vol. XXI. No. 5.37. 



mixed with other microbes and in such form 

 that it may be studied by various methods. 



The Formation of the Centrosome in Enucle- 

 ated Egg-fragments : Naohide Yatsu. 

 To test whether the centrosome is a perma- 

 •nent cell-organ or not, Wilson (1901) treated, 

 with a salt solution, enucleated egg-fragments 

 (sea-urchin) obtained by shaking. He ob- 

 served that asters containing centrioles and 

 capable of division were produced in this way 

 in the enucleated fragments. At Wilson's 

 suggestion the author tried the experiment in 

 a somewhat different manner. Eggs of Cere- 

 hratulus were used. Individual eggs were cut 

 into nucleated {i. e., containing the first 

 maturation mitotic figure) and enucleated 

 fragments. The latter were kept for an hour 

 In a solution of calcium chlorid. Then they 

 were transferred to sterilized sea-water. As- 

 ters were produced in almost all enucleated 

 fragments thus treated. All the asters had 

 centrioles which were identical with those 

 found in the whole eggs subjected to the same 

 treatment. The nucleated half was stained 

 and was shown to have had two original cen- 

 trosomes intact. From the results of these 

 -experiments no other conclusion can be drawn 

 than that the centrosome, with centriole, of 

 the enucleated fragment was in each case 

 formed de novo — a complete confirmation of 

 Wilson's original deduction. 



In these experiments strict precautions were 

 taken to prevent accidental fertilization. 



Structure of Vaccine Bodies in Isolated Cells, 

 with demonstrations: James Ewing. 

 In Klatsch preparations of corneal vaccine 

 ulcers stained by Nocht's method, the vaccine 

 body is seen to be a portion of the cytoreticu- 

 lum, its reticular structure being continuous 

 on the one hand with the cytoreticulum and 

 on the other usually with the nuclear reticu- 

 lum. The clear zone surrounding the vaccine 

 body in sections of tissue is an artifact. The 

 reticulum of the vaccine body takes the chro- 

 matin stain, indicating that it contains chro- 

 matin, and many of the bodies are so inti- 

 mately connected with the nucleus, the meshes 

 of one passing insensibly into the other, as to 

 force the conclusion that these particular 



bodies have arisen by recent extrusion of nu- 

 clear chromatin into the cytoreticulum. Other 

 bodies are disconnected from the nucleus and 

 these may have arisen partly from the chro- 

 matin of the cytoplasm, a possibility which is 

 furnished by Hertwig's theory of the consti- 

 tution of cell protoplasm. Many of the vac- 

 cine bodies closely resemble the chromidial 

 substance described by Hertwig in some lower 

 animal cells. In the meshes of the reticulum 

 the author has been unable to demonstrate 

 any organized structure, but the meshes some- 

 times present nodal points of an underlying 

 reticulum. In the fresh condition the meshes 

 contain homogeneous refractive globules which 

 disappear on drying. 



Two series of changes may be followed in 

 the vaccine bodies in BHatsch preparations. 

 Many of them develop basic staining areas 

 with loss of the central reticulum, and this 

 process may continue until the entire body is 

 transformed into a homogeneous globule re- 

 sembling mucus or colloid. In others the 

 reticulum breaks up into granules with or 

 without the development of a central basic 

 mass. 



The author has been unable at any stage or 

 in any derivative of the vaccine body to detect 

 the slightest definite trace of a protozoon. 

 Besides vaccine bodies there are other struc- 

 tures resembling protozoa to be seen in 

 Klatsch preparations. They appear to be pe- 

 culiar cell granules and are present in normal 

 animals. 



On the Tetanic Element in Bile: S. J. 



Meltzer and William Salant. 



The authors have shown that the injection 

 of bile can produce tetanus as well as coma. 

 The latter is the more constant symptom. By 

 the use of subminimum doses of strychnin a 

 tetanic element could be shown to occur in bile 

 that infallibly produced coma. A frog of 

 medium size will not respond, even with the 

 slightest hyperesthesia, to an injection of one 

 hundredth of a milligram of strychnin. When 

 such a small dose, however, is injected into a 

 frog which had received a certain quantity 

 of bile, the animal reacts, sooner or later, with 

 a distinct tetanus. The effective dose of bile 

 varies with the animal from which it is ob- 



