XVIII Journal of Agricultural Research voi.vi 



Page 



Platu CI. Fig. I.— The bench. The cotirse of Rock Creek is indicated by the 



distant trees. Fig. 2. — Part of a reservoir on the Rock Creek ranch 760 



Plate CII. Fig. i. — Lupin recessive and cat 's-f&ot becoming dominant. Gay's 



sedge subphase in background. Fig. 2 .—Wheat-grass phase 760 



Plate CIII. Fig. i.— Squirrel-tail phase. A few grindelias in the foreground. 



Fig. 2.— Rush-sedge phase (the darker areas) replacing wheat-grass phase. 760 



Plate CIV. Fig i.— Hair-grass phase. Fig. 2.— Natural meadow 760 



Plate CV. Fig. i .—Field of oats on bench. Cat's-foot and other upland plants 

 in foregroimd. Fig. 2.— Alfalfa field one year after sowing. Cat's-foot and 

 bench grasses in foreground 76° 



Agricultural Value op Impermeable Seeds 



Plate CVI. Fig. i. — A row of alsike clover from impermeable seeds between 

 two rows from permeable seeds. Fig. 2 . — A row of white clover from imper- 

 meable seeds between two rows from permeable seeds 796 



Life-History Studies op Cirphis unipuncta, the True Army Worm 



Plate CVII.— ^, Cages for rearing Cirphis unipuncta; B, leaves glued together 

 after the eggs have been deposited; C, characteristic leaves partly eaten by 

 first-instar larvae; D, full-grown larva; E and F, characteristic pupal cells. 812 



Control op the Powdery Dryrot of Western Potatoes Caused by 

 Fusarium trichothecioides 



Plate CVIII. Fig. i. — A potato tuber infected with powdery dryrot, showing 

 the wrinkled condition of skin due to the decay of underlying tissues. 

 Fig. 2. — A potato tuber infected with powdery drj'^rot. Advanced stage. 

 Fig. 3. — Section through a potato tuber infected with powdery dryrot, 

 showing the internal cavities filled with the mycelium and the spores of the 

 fungus 832 



Thersilochus conotracheli, a Parasite op the Plum Curculio 



Plate CIX. Thersilochus conotracheli: Fig. i. — Adult female. Fig. 2. — a, 



Adult male ; b, side view of abdomen 856 



ApHIDOLETES MERIDIONALIS, AN IMPORTANT DIPTEROUS EnEMY OP ApHIDS 



Plate CX. Aphidoletesmeridionalis: Fig. i. — ^Adult female : a, Antenna of male, 

 showing structure; h, tip of male abdomen. Fig. 2. — Larva attacking a 

 pea aphis 888 



Progressive Oxidation of Cold-Storage Butter 



Plate CXI. — Gas apparatus used in the extraction and analysis of the air 



confined in butter 952 



Studies on the Physiology of Reproduction in the Domestic Fot\t.. — 



XV. Dwarf Eggs 



Plate CXII. — A collection of dwarf eggs with a normal egg in the center of 



the group 1042 



Plate CXIII. — Fig. i. — Ovarian follicles {b-f) and the dwarf egg a from case 27. 

 Fig. 2. — Shell of a compound egg Avhich was composed of two albumen 

 masses partly separated at the level of the seam in the shell by an incom- 

 plete egg membrane. Fig. 3. — Dwarf egg containing a mass of yolk not 

 in a yolk membrane, but separated from the albumen by a membrane- 

 like layer of chalazal threads. Fig. 4. — Dwarf egg formed around an 

 artificial yolk of agar which was inserted into the oviduct, o, Complete 

 egg; b, agar yolk 1042 



