ANNUAL REPORT, 1935 19 



The above evidence indicates that the tunica dartos is dependent upon a 

 testicular hormone for its development and function. 



The Speed of Travel of Ram Spermatozoa. (Ralph W. Phillips and Fred 

 N. Andrews. ) The speed at which ram sperm travel in vitro in Ringer's and 

 in normal salt solutions, over a distance comparable to the distance traveled 

 in the ewe, has been found to be 4.6 mm. per minute. The rate is much faster 

 at first and slower at later stages. 



Seven ewes have been slaughtered at intervals of one half to seven hours 

 after being artificially inseminated with semen diluted with Ringer's solution. 

 At all stages sperm have been found in the upper section of the fallopian tubes. 

 Previous work has set the time to cover this distance at five to six hours. The 

 marked difference may be partially accounted for by the dilutor used. 



Efficiency of Feed Utilization in Lambs. (Ralph W. Phillips.) A two- 

 year study of the efficiency with which lambs utilize feed has shown that marked 

 variations exist. In the first year's work, variations up to 17 percent were 

 observed in seven Southdown lambs, and up to 41.2 percent in three Shrop- 

 shires. In the second trial, variations up to 118 percent were observed in ten 

 Shropshire lambs. 



The Relation of Birth Weight to Growth Rate in Lambs. (Ralph W. 

 Phillips. ) A study of the birth weights of 108 Southdown lambs shows that 

 lambs weighing 6 pounds and over have a better chance of surviving and make 

 greater gains. Of all lambs weighing 6 pounds and under, 32 percent were born 

 dead or died within a month after birth; while only a 7 percent loss was found 

 in the heavier lambs. The heavier lambs also made greater gains during their 

 first year of life. 



DEPARTMENT OF BACTERIOLOGY 

 Leon A. Bradley in Charge 



Microbiological Examination of Dried Foods. (J. A. Clague and James 

 E. Fuller. ) Dried fruits and dried vegetables were examined for the numbers 

 and types of microorganisms present. Dried fruits were found to be con- 

 taminated only on the surface, due to the fact that they are dried and marketed 

 either whole or cut into halves. The microorganisms were not numerous and 

 consisted largely of yeasts and non-pathogenic Gram-positive sporulating 

 bacteria. Dried vegetables are marketed in powdered form and consequently 

 the microorganisms present are mixed with the vegetable material. The micro- 

 bial content of dried vegetables was much greater than that of dried fruits, 

 but the same types of organisms were present. In addition some Gram- 

 negative lactose-fermenting bacteria were found but these were not typical 

 Escherichia coli. Artificial dehydration in a tunnel drier eliminated yeasts and 

 reduced the numbers of bacteria and molds on dried fruits. Escherichia coli 

 inoculated onto the surface of the fruits was killed. Dehydration was less 

 successful in reducing the numbers of microorganisms, including added Escheri- 

 chia coli, on dried vegetables. When vegetables were blanched before being 

 dehydrated, Escherichia coli was destroyed by the process. Media found useful 

 in the study were nutrient agar for bacteria, and tomato agar for yeasts and 

 molds. 



