98 BOTANICAL GAZETTE [january 



fungus the oogonial hypha pushes its way entirely through the antheridium, 

 and, after emerging on the side opposite to the point of entrance, enlarges to 

 form the oogonium. This unusual process, together with the subsequent 

 events in the formation of the oospore, has now been more fully investigated 

 by Murphy,' whose cytological evidence bears out the observations of Pethy- 

 BRIDGE. The antheridia and oogonia are found to arise on different branches 

 of the mycelium. During the penetration of the antheridium by the oogonial 

 incept no fusion of the cytoplasm of the two organs occurs. After its emergence 

 the oogonial hypha develops into a more or less spherical multinucleate oogo- 

 nium whose stalk passes through the antheridium. When the sexual organs 

 have reached their full size, about two-thirds of the nuclei in the antheridium 

 and in the oogonium degenerate. The remaining nuclei in both organs then 

 divide once mitotically and simultaneously. During the division the nuclei 

 of the oogonium are arranged in a hollow sphere, with the exception of one, 

 which remains in the center. Immediately after the division the protoplasm 

 of the oogonium separates into a vacuolate hyaline ooplasm and a denser peri- 

 plasm. In the oogonium, and probably in the antheridium also, all the nuclei 

 but one degenerate. During this period a prominent receptive papilla pro- 

 trudes from the base of the oogonium into the antheridium. When the recep- 

 tive papilla is withdrawn, the fertilization tube grows into the oogonium at the 

 same point and discharges one nucleus and the greater part of the cytoplasm of 

 the antheridium into the oogonium. With the completion of this process most 

 of the periplasm has disappeared and the oospore is surrounded by a thin mem- 

 brane with the last vestiges of the degenerating nuclei appressed against its 

 outer surface. The fusion of the two nuclei does not take place until the 

 thickened oospore wall has been completed. — H. Hasselbring. 



Action of neutral salts on acid inversion of cane sugar. — Lebert'" has 

 studied the action of neutral salts on the acid inversion of cane sugar. His 

 resxilts furnish him a basis for a chemical explanation of certain difficulties some- 

 times encountered when attempts are made to invert cane sugar by means of 

 w'eak acids or stronger acids in quantity just sufficient to effect the inversion. 

 Solutions in which it is desired to invert cane sugar are rarely free from neutral 

 salts, especially sodium acetate left in the solution after clearing with lead 

 acetate and removing the excess of lead with sodium carbonate or sulphate. 

 If the hydrolysis is effected by a relatively large quantity of strong acid, as in 

 the Clerget method, the presence of a small amount of salt is of little conse- 

 quence, since the H ions are in great excess. If organic acids are employed, the 

 presence of their sodium or potassium salts will retard the rate of inversion, 



9 Murphy, P. A., The morphology and cytology of the sexual organs of Phytoph- 

 thora erythrose plica Pethyb. Ann. Botany 32:115-153. pis. 3. 1918. 



"Lebert, M., Action des sels neutres sur I'inversion du sucre par les acides. 

 Rev. Gen. Botanique 30:241-244. 1918. 



