From this point into the 1930s, features of field guides were introduced by Chester A. Reed and others such as changing the size of the book to fit the pocket, including colour plates, and producing guides in uniform editions that covered subjects such as garden and woodland flowers, mushrooms, insects, and dogs.
Desde este punto ata a década de 1930, características das guías de campo foron presentadas por Chester A. Reed e outros, como cambiar o tamaño do libro para coller no peto, incluíndo ilustracións a cor, e producindo guías en edicións uniformes que cubriron asuntos como xardíns e flores de bosque, cogomelos, insectos e cans.