Shamel: Why Navel Oranges Are Seedless 



249 



dance of pollen falls on to the sticky stig- 

 matic surface. Here the pollen grains 

 germinate and send their pollen tubes 

 down through the pistil to the ovules 

 where fecundation takes place. 



LUDICROUS MISTAKES MADE 



The lack of pollen in the flowers of 

 the Washington navel orange variety 

 is responsible for some rather ludicrous 

 mistakes by some so-called breeders of 

 new orange varieties. Every little while 

 the writer receives a letter from, or 

 comes into contact with, men who 

 claim that they have originated a 

 wonderful new orange by crossing the 

 Washington navel orange with the 

 Marsh grapefruit or some other citrus 

 variety. Usually, they say that the 

 pollen from the navel orange flowers 



has been used in making the alleged 

 cross. An examination of the navel 

 orange trees from which they claim to 

 have gotten their pollen has invariably, 

 so far, revealed the fact that there was 

 no pollen in the flowers borne by these 

 trees. These men, in some cases old 

 orange growers, become very angry 

 when the pollenless condition of their 

 Washington navel orange flowers is 

 pointed out to them. 



The seedless characteristic of the 

 navel orange is thus explained by a 

 recent visitor to Southern California: 

 "When the navel oranges are young the 

 growers go about with a knife and per- 

 form an operation. The scars left by 

 the knife when the seeds are cut out 

 can be plainly seen at the ends of the 

 oranges." 



Stallion Enrollment Work for 1917 in Indiana 



In spite of the fact that the number 

 of mares bred last year was smaller 

 than usual, the Purdue University Ag- 

 ricultural Experiment Station, in Cir- 

 cular No. 7Z, reports an increase in the 

 number of registered pure-bred stal- 

 lions and a decrease in the number of 

 grade and scrub stallions and jacks 

 enrolled. 



The 3'ear 1917 passed wath very sat- 

 isf actor}' relations between stallion 

 owners and the Enrollment Board. 

 Owners secured their renewals earlier 



than ever before, and on March 15 it 

 was found that but few were still 

 delinquent. 



Due to the fact that the market price 

 of horses has not advanced as has that 

 of cattle and hogs, the amount of 

 breeding^ done was below the average, 

 but that which was done appears to 

 have been carried out along scientific 

 lines. Many communities have organ- 

 ized horse breeders' associations, and 

 through these are helping establish 

 breeding on a sound basis. 



Butter Fat Percentage Independent of Age of Cow 



In the study of factors for produc- 

 tion it is very important to know if 

 there is any correlation between age 

 and butter fat test in cows. The mean 

 yearly fat test of eighty-six cows in 

 the Delaware College herd has been 

 studied in relation to age of the cows. 

 Some of these cows have more than 

 one record, and the number of records 

 studied is 104. 



The ages of the cows range from 

 one and one-half to fourteen and one- 

 half years, and the mean yearly fat 

 tests show a range of from 3.25% to 

 7%. The standard deviation in age is 

 2.54 ±.119 years. The standard de- 



viation in fat test is .74 ± .035%. 



The coefficient of correlation, calcu- 

 lated by the usual formula, is • — .196 

 ± .064. Since this coefficient is barely 

 three times the probable error, it can- 

 not be considered at all significant. 



The only deduction that follows, 

 therefore, from these studies is that the 

 butter fat test of the milk of a cow is 

 not at all influenced by the age of the 

 cow. This being the case, the study 

 of the hereditary behavior of the per- 

 centage of butter fat in the milk of 

 cows of different ages does not in any 

 way affect the accuracy of the results. 



