280 



SCIENCE 



[N. S. Vol. XXXVIII. No. 973 



diseased bark or both in tbe movements of the 

 birds over these surfaces. This conclusion is 

 supported by the fact that the birds tested 

 were not carrying ascospores; that we have no 

 evidence that ascospores are washed down the 

 trees during the winter and spring months;" 

 also that following a rain period pycnospores 

 are to be found in abundance on the healthy 

 bark below blight lesions. 



F. D. Heald 

 R. A. Stcdhalter 

 Forest Pathology Laboratoey, 

 U. S. Department of Agriculture, 

 Philadelphia, Pa. 



the eelation between abnormal permeability 

 and abnormal development of fundulus 



EGGS 



In a previous paper' the suggestion was 

 made that certain abnormalities in Fundulus 

 embryos are caused by increase in permeability 

 since osmotic pressure is not the cause and so 

 many diiferent substances have the same effect. 

 It was found that the normal egg in distilled 

 water or a " balanced " salt solution is imper- 

 meable to salts (Appendix II.). The egg ap- 

 peared to be impermeable to water also, since 

 enormous osmotic changes have no effect on it. 

 The egg was found to contain nearly three 

 times as much ash as sea water. The greater 

 part of the ash is insoluble, but some of it may 

 have been rendered so by the ashing. How- 

 ever, the soluble ash (.3.18 per cent.) is as great 

 as the total salts (2.84r-3.29 per cent.) in the 

 local sea water. And yet the egg develops 

 normally, with little or no change in volume, 

 in distilled water or in sea water that is evapo- 

 ratd to one half its volume, suggesting im- 

 permeability to water. The fact that the eggs 

 dry up when exposed to air may be taken to 

 indicate an increase in permeability to water, 

 due to drying of the superficial layer or plasma 

 membrane. 



"Heald, F. D., and Gardner, M. W., "Prelim- 

 inary Note on the Relative Prevalence of Pycno- 

 spores and Ascospores of the Chestnut Blight 

 Fungus during the Winter," Science, N. S., 37: 

 916-917, 1913. 



"MeClendon, Am. Jour. Physiol., 1912, XXIX., 

 p. 290. 



In the same paper some preliminary chemi- 

 cal studies of the permeability were described, 

 and the view advanced that the egg is normally 

 impermeable to Mg ions, but since Mg was 

 found to diiiuse out of the eggs in a pure NaOl 

 solution, this solution may have increased the 

 permeability to Mg (p. 296). Only one experi- 

 ment to test the permeability to anions was 

 described. MgSO^ solution was used, with 

 negative results. However, the MgSOj con- 

 tained too large a trace of chloride to make it 

 possible to detect a very small difiusion of 

 chloride from the eggs. 



During the present season I was able to 

 obtain especially pure salts, and have observed 

 diffusion of both anions and kations from the 

 eggs in pure solutions of these. The mon- 

 strosities produced in unbalanced salt solu- 

 tions have also been studied. The experiments 

 support the following generalizations: 



1. Any solution of one or more of the salts 

 of sea water, which is sufficiently unbalanced 

 by other salts, i. e., has a certain excess of 

 some one kation, produces a number of types 

 of monstrosities in Fundulus eggs. The types 

 of monsters produced by the excess of one ka- 

 tion (e. g., Na) are the same as those produced 

 by any other (e. g., K, Ca or Mg). Thus a 

 qualitatively specific action of a salt or ion 

 does not exist. 



2. These unbalanced salt solutions cause an 

 increase in the permeability of the egg to 

 salts. This conclusion is based on the follow- 

 ing data: The eggs in distilled water or in 

 van't Hoff's solution (made with nitrates) lose 

 no salts or ions that can be detected, except 

 the ions of carbonic acid. On the contrary, 

 the eggs give out salts or their ions in a mix- 

 ture of NaCl and KCl or in pure solutions 

 of the following salts : NaCl or nitrates of Na, 

 K, Ca or Mg in concentrations that do not 

 Mil the eggs during the experiment. If the 

 eggs are killed a more rapid diffusion takes 

 place. The methods used will be published 

 elsewhere. 



J. F. McClendon 

 U. S. Bureau op Fisheries, 

 Woods Hole, Mass., 

 July 25, 1913 



