212 M. F. GUYER 



visible at one or two places of the microscopic field for over twenty 

 minutes. In corresponding dilutions of the normal fowl serum 

 motion continued for hours. 



Experiment 2 



In the meantime, in April, a new set of experiments was 

 begun. April 1st five fowls were injected subcutaneously (two 

 injections in one of the fowls were intravenous) with the semen 

 from four male rabbits, obtained from females as in the earUer 

 experiment. Sufficient normal saline solution was added to 

 the semen to make a dose of 3 cc. for each fowl. One fowl died 

 two days later. April 8th, the remaining four fowls were injected 

 subcutaneously with the semen from three male rabbits, and 

 this treatment was repeated on April 15th, April 24th, and May 

 1st. Two males, 25 and 83, were selected for tests with the 

 spermatoxic serum. Both were first mated to test their fertility 

 by breeding and by microscopic examination. 



Male 25 was mated to 52A5 on April 13th (three young were 

 born of this union) and microscopical examination of his sperma- 

 tozoa showed them to be very active and plentiful. Samples 

 placed in the sensitized fowl-serum were markedly agglutinated 

 and all were inmaobilized within three minutes. He was given 

 intravenous injections of the sensitized fowl-serum as follows: 

 May 15th, 3.5 cc; May 17th, 4 cc; May 20th, 4.5 cc; May 26th, 

 4.5 cc; May 28th, 4.5 cc. On May 22nd his semen showed a 

 reduced number of spermatozoa with many immobile ones in 

 the field; however, others showed considerable activit}^ A 

 mating to female 32A2 on this date yielded seven young. On 

 June 12th, though much reduced in numbers, many of his sper- 

 matozoa as seen under the microscope were active. A mating 

 to female 4A3 yielded no young. July 10th, while his sperma- 

 tozoa were much reduced in numbers, some were still active, 

 although most of those visible were immobile. Female 54 A3, to 

 which he was bred on this date, had no young. On October 6th 

 his sperm was again examined microscopically. While reduced 

 in quantity to what a rough estimate placed at one-fourth 



