PARENTAL ALCOHOLISM AND THE PROGENY 273 



many cases not the same for the treated and the untreated 

 series. On this account as well as others a comparison between 

 the different series in respect to growth can best be made by 

 graphical means. To this end figures 2 and 3 have been pre- 

 pared. It will be noted from these figures that the weighings 

 were carried into adult life in the case of both sexes. They stop 

 somewhat earlier in the case of the males than the females 

 owing to considerations of space on the plant. It scarcely 

 needs to be said that the utmost care was used to ensure accu- 

 racy in this growth work, and to keep the surrounding condi- 

 tions of housing, feed, etc., in every respect favorable to normal 

 growth. The latter point is, of course, a very important one 

 for critical results. The favorableness or unfavorableness for 

 animal growth of the general environmental conditions, the 

 season,' etc., is not a thing which can be exactly measured, but, 

 it may be judged by one experienced in the husbandry of the 

 particular animals dealt with. On such general observational 

 grounds one would have judged that the season and general 

 environmental conditions surrounding the chickens in 1913, the 

 year in which the control chickens ex untreated cf cf X untreated 

 9 9 were grown, were more favorable to growth than in 1915, 

 the year in which the offspring of alcoholized parents were 

 grown. If such was in fact the case, and my observations lead 

 me to believe that it was, the results obtained, as will presently 

 appear, take on added significance. 



It should be particularly noted that no question of artificial 

 selection can enter as a factor in influencing the growth data 

 for the simple reason that no such selection was practiced. 

 Each and every individual chicken was regularly weighed as long 

 as it lived or until it reached maturity and the weighing records 

 came to an end for the season. As the mortality was small 

 it practically means that there was no selection at all between 

 hatching and maturity. In the case of weighings of females 

 at ages over 210 days there has been a selection. The indi- 

 viduals at these higher ages are the ones kept over for winter 

 egg production and to be used -as breeders the next year. Great 

 care was taken, however, to ensure that the samples chosen 



THE JOURNAL OP EXPERIMENTAL ZOOLOGY, VOL. 22, NO. 2 



