DAIRY FARMING DAIRYING AGROTECHNY. 1073 



"In tlu' most vi.uorous birds wilh louy ])luuios the wing feathers grow at 

 least 1.75 in. per week or 0.25 iu. per day ; in weiikly birds the growth in length 

 may be .scarcely half these amonuts. 



•■ The rate of growth varies in different ostriches, dependent niton tlu; strain 

 of the bird and the condition of health of the bird. Under certain conditions 

 of health growth may cease altogether, or the appearance of new feathers may 

 be long delayed." 



Observations on the fixation of oyster spat at Barnegat, N. J., 1907, 

 J. Nelson (New Jersey Stus. lipt. 1007, pp. 207-256, pis. J3). — The qnotations 

 which follow are taken from the author's summary of the results of his studies 

 of oyster propagation carried on iu continuation of earlier work (E. S. It., 19, 

 1). G77), the investigations this season being confined to natural spatting in a 

 single locality. 



" The eggs developed so rapidly that filtration of the water showed the pres- 

 ence of oyster larv;e, practically, only after they are iu the shell stage. In this 

 stage, called the protcconch stage, there is steady growth for at least a week, 

 and jtossibly three weeks, with a great loss by death, until the fry are ready to 

 attach themselves to cultch. . . . 



"At the time of ' setting ' there had been an increase iu bulk, approximately, 

 60 times that of the young in the first protoconch stage, and the two valves of 

 the shell, though at first ecpial, have by this time become unequal, the umbo of 

 the left valve being more prominent than that of the right. 



" The fry settles down on the surface of the cultch on the velum and mantle 

 folds, and cements the edge of the left valve fast to the cultch. Then there is 

 added a fringe of shell to both valves, that of the left being cemented fast to 

 the cultch. At the hinge this so-called silphologic addition projects iu a straight 

 line x)n each side, inclined at an angle to each other. These silpho additions 

 are repeated constantly, enlarging the size of the shell, until by two weeks an 

 area, 3 mm. in diameter, is covered. . . . 



" Experiments in the artificial propagation of oyster fry did not succeed until 

 the oysters were spawning. 



"Only those lots that developed a']>n)toconch were considered to have been 

 successful. . . . 



" In our experiments involving daily plantings, the best shells caught from 

 loo to over 200 natural spat iu from 3 to 5 days. 



" The young si)at can be recognized by means of a magnifying glass, fi-om the 

 vei*y hour it becomes attached. . . . 



"By means of the filtration of sea water it is jiracticable to keep record of 

 the development of natural fry, so that the date when shells should be planted 

 can be quite accurately determined." 



DAIRYFARMING— DAIRYING— AGROTECHNY. 



Report of the dairy husbandman, (1. A. Billings (Xcw Jersey ^las. Rpt. 

 1007, pp. 39-56). — Two feeding experiments are reported, in one of which the 

 object was to study the effect of a large amount of dried corn distillers?' grains 

 iu the ration, and the other to study the problem of summer fiH'ding of dairy 

 cattle with respect to whether corn silage can be used as a substitute for forage 

 crops or pasturage. 



In the study of the value of distillers' grains v. ground oats, gluten feed, oil 

 meal, and bran in a ration for milcli cows it was found that the ration contain- 

 ing G* lbs. daily of drietl distillers' grains was very profitable and that the 

 animals maintained their thrifty condition on it. This ration cost 23.2 cts. 

 per day as compared with 28.39 cts. for the ordinary grain ration. The cost of 



