The Official 

 Or^an is The 

 Nature Study 

 Review 



Devoted primarily to 

 all Scientific Studies 

 of Nature in Elemen- 

 tary Schools. It is 

 published monthly ex- 

 cept June, July and 

 August, Elliot R. 

 Downing, Editor. 



From W. E. Cas- 

 tle's article, Novem- 

 ber, ipii, "Guinea 

 Pigs." 



from W. L. Os- 

 ivald's article, Janu- 

 ary, I912, on "Seed Fig. 1 crop)— Self-Colored English Guinea-Pig. 

 T-,^- ,, » Fig. L> (Middle) — I)utch-Marke<l English (Uiinea-Pig. 



1 esimg. Fig. .3 (Bottom)— Albino English (kilnea-Pig. 



I'lc. 4. Tkii'oi) Lens .\.\i) I'okceps Tsed i.\ M.\ki.\g Purity 



Tiisrs. 



