June 30, 1911] 



SCIENCE 



999 



kept alive in laboratory dishes for some days, 

 but underwent no further change. 



Dr. E. P. Lyon and Mr. L. T. Shackell, of 

 St. Louis University, vcorked upon problems 

 connected with the fertilization of the ovum, 

 directing their attention particularly to the 

 chemical differences between fertilized and 

 unfertilized eggs, using for the most part 

 sea-urchin material. 



A large amount of material for chemical 

 analysis was collected which is to be worked 

 up in the Physiological Laboratory of St. 

 Louis University; also at Chicago through 

 the cooperation of Professor Waldemar Koch, 

 of the University of Chicago. 



Messrs. Lyon and Shackell studied the 

 changes in permeability occurring in eggs 

 resulting from fertilization, and a preliminary 

 article on this work was published in Science, 

 August 19, 1910. 



Dr. E. W. Gudger, professor of biology and 

 geology. State Normal College, Greensboro, 

 K". C, spent ten weeks at the laboratory be- 

 ginning May 25. 



Owing to the difficulty in getting eggs and 

 embryos in May and early June, he was un- 

 able to complete his series for the life history 

 of the gaff-topsail catfish. He now lacks only 

 the segmentation and the earliest invagination 

 stages. He was very successful, however, in 

 hatching the eggs and rearing larvae. 



He was also successful in getting about half 

 the stages for the life history of the butterfly 

 ray, and hopes to complete this series next 

 season. Some of these larvse are very extra- 

 ordinary in form. 



In his work with the spotted sting ray, he 

 was fortunate in obtaining three perfect 

 specimens, two of them alive. Erom these it 

 is hoped that certain variations in color, spots 

 and teeth may be explained. 



Careful photographic records were made of 

 all the material referred to above, and an 

 artist (Mr. E. A. Morrison, Jr., of Baltimore), 

 under a grant from the Carnegie Institution, 

 spent two weeks making drawings, chiefly of 

 early stages of the gaff-topsail catfish. 



Dr. H. S. Davis, of the University of Flor- 

 ida, worked at the laboratory during por- 



tions of July and August. The time was 

 spent in examining fishes for parasitic proto- 

 zoa and in observations on the morphology 

 and life history of the parasites found, the 

 work being largely of a preliminary nature to 

 serve as a basis for further more detailed in- 

 vestigations. 



A total of 26 species of fishes were exam- 

 ined for protozoan parasites. In the case of 

 several of the more common species many 

 individuals were examined, but with the rarer 

 species the investigation was often necessarily 

 limited to the, examination of one or two speci- 

 mens. Most of the parasites found were 

 Myxosporidia, and of the 26 species of fish ex- 

 amined 14 were found to be infected with 

 these parasites. As is usually the case, the 

 gall-bladder was found to be most com- 

 monly infected, 13 out of the 14 species 

 showing infection of this organ. In 2 species 

 both the gall- and urinary-bladders were 

 infected, but, of course, by different species 

 of Myxosporidia. In a few cases the gall- 

 bladder was found to be simultaneously in- 

 fected with 2 species of Myxosporidia. In 

 most cases the percentage of infected individ- 

 uals was high, sometimes reaching 100 per 

 cent. This was found to be especially true of 

 the adults which were much more commonly 

 infected than the young of the same species. 

 It is significant that, in the case of those 

 species in which Myxosporidia were not found, 

 usually only one or two individuals were 

 available for examination and these were often 

 immature. 



In the case of all the species of fish found 

 to be infected no myxosporidian parasites 

 have previously been recorded. 



The Myxosporidia found belong to 6 genera, 

 as follows, the species in many cases being ap- 

 parently undescribed: Sphosrospora, Sphosro- 

 myxa, Chloromyxum, Ceratomyxa, Myxoholus 

 and Henneguya. In several cases, on ac- 

 count of the absence of material in the proper 

 stages, it was found impossible to determine 

 the genus. 



In at least two cases the same species of 

 Myxosporidia was found to occur in two or 

 more species of fish. 



