OCTOBEE 11, 1907] 



SCIENCE 



471 



vivors, two are large and apparently normal 

 and two are undersized. Only one individual 

 out of 150 eggs, fertilized by sperm exposed 

 37 minutes to the rays, has survived one 

 month and this individual is only half the 

 normal length and breadth. In a group of 

 250 eggs, fertilized by sperm exposed to 

 Roentgen rays for an hour and ten minutes, 

 all exhibited marked abnormalities of de- 

 velopment and the least abnormal larva and 

 longest survivor died a week after the eggs 

 were fertilized. 



The susceptibility of sperm of anura to 

 X-rays is in marked contrast to that of para- 

 mecia. Exposure of paramecia for 12 hours 

 to rays of the same intensity caused no visible 

 effects on form, rate of division or process of 

 conjugation. 



The author exposed the sperm of the toad 

 to heat at 50° and 65° C. for from 15 to 20 

 minutes. This exposure destroyed the fertiliz- 

 ing power of most of the spermatozoa, but the 

 few eggs fertilized by such sperm developed 

 normally. Sperm exposed for from 15 to 20 

 minutes to the following solutions : 1/40 per 

 cent, formol, 12.5 per cent, ethyl alcohol, 1 

 per cent. NaCl, 1/32 per cent. HCl and 1/32 

 per cent. KOH, had the power of fertilizing 

 toad eggs. Practically all of the resulting 

 larvas that have been preserved appear normal 

 at the end of one month after fertilization 

 of the eggs. Sperm exposed to stronger solu- 

 tions of the same substance for 15 to 20 

 minutes seems to lose power of fertilizing. 

 ~No abnormal larvas have developed from the 

 few eggs thus fertilized. 

 On the Aisorpiion of Toxins hy the Nerves: 



Cyrus W. Field. 



In a large number of animals into which 

 both tetanus and diphtheria toxin had been 

 injected, Field found that the toxin was 

 present in the peripheral nerves leading from 

 the inoculated area; and by the use of the 

 right dose, and at a certain time, free toxin 

 could be demonstrated in the cord, although 

 the other tissues of the body, including the 

 blood, liver, spleen and kidneys, contained no 

 free toxin. 



Not only is this true for diphtheria and 



tetanus, but it is likewise true for the toxin 

 produced from B. hotiilinus and also for col- 

 loidal ferric hydrate. In the case of colloidal 

 ferric hydrate, by removing the nerves and 

 cord, and subjecting them to treatment with a 

 solution of hydrogen sulphide, Field was able 

 to detect the presence of iron. By using small 

 doses he was able to show the presence of 

 these colloids in the nerves near the points of 

 injection and in the spinal cord, but of none 

 whatever in the other tissues, except at the 

 points of inoculation. 



The author concluded that tetanus toxin 

 does not travel by way of the axis cylinder 

 because of any specific attraction of the 

 nerve tissue for this toxin, but it passes up 

 because the lymphatic flow of the nerve is 

 progressing constantly from the periphery to 

 the center. For this reason the toxin, when 

 injected subcutaneously or intramuscularly, is 

 taken up by the nerves and passes to the cord ; 

 and the first symptom to develop is the local 

 tetanus because the local cells are the first that 

 come in contact with the toxin. 



It is a well-known fact that in giving diph- 

 theria or tetanus toxin intravenously a much 

 greater dose is required to cause death than 

 when either is injected subcutaneously or 

 intramuscularly. The reasons for this are 

 first, that the toxin injected into the blood 

 may be combined with some of the constit- 

 uents of the blood and therefore rendered in- 

 active; second, that by injection into the 

 blood the toxin is diluted to a very great ex- 

 tent, whereas when injected subcutaneously, a 

 portion passes into the lymphatics of the 

 nerves and is not mixed with the general body 

 fluids, before it reaches the central nervous 

 system. 



The author's general conclusion was that 

 tetanus does not travel up a nerve by reason 

 of any specific attraction of nervous tissue, 

 but because the lymphatic flow in a nerve is 

 from the periphery toward the center. 

 Ori the Formation of a Specific Precipitin in 



Rahhits after Inoculation with Colloidal 



Platinum and Colloidal Silver: Cyrus W. 



Field. 



Some time ago in testing the precipitating 



