It must be noted also that cambium is a very delicate, perishable material, at certain times no more than a jelly, and thus never receives a percentage valuation in examinations of long-preserved stomachs corresponding to its bulk when first swallowed. Neither do we get any record of the sap consumed by these birds [the three species of sapsucker] and they are inordinate tipplers. Hence the value of the percentages cited lies not so much in their accuracy as to the quantity of cambium eaten as in the fact that they indicate a steady consumption of this important substance. There is no doubt that cambium, bast, and sap are depended upon by sapsuckers as stable diet. We may get some idea of the amount of sap consumed by the bird from Frank Bolles’ (1892) record of his three young captive sapsuckers. He says: “Ordinarily they disposed of eight teaspoonfuls [of diluted syrup] each during the twenty-four hours. Part of this evaporated, and part was probably secured by black ants which visited the cage by night.” Bolles (1891), describing the method of feeding of birds in the wild, says: “The dipping was done regularly and rather quickly, often two or three times in each hole. The sap glistened on the bill as it was withdrawn. I could sometimes see the tongue move. The bill was directed towards the lower, inner part of the drill, which, as I found by examination, was cut so as to hold the sap.” This is the common method of feeding, but sometimes, when two or more holes have coalesced into a vertical groove, the bird will run its bill upward along the edge of the wound, sipping the sap much as we might, with our finger, wipe off a drop running down from a pitcher’s lip. McAtee (1911) states that “about four-fifths of the insect food of the three species of sapsuckers consists of ants, the eating of which may be reckoned slightly in the birds’ favor. The remainder of the food is made up of beetles, wasps, and a great variety of other insects, including, however, practically no wood-boring larvae or other special enemies of trees. The birds’ vegetable food can not be cited in their behalf, as it consists almost entirely of wild fruits, which are of no importance, and of cambium, the securing of which results in serious damage.” F. E. L. Beal (1895) mentions, as articles in the sapsucker’s diet, the berries of dogwood, black alder, Virginia creeper, and wild black cherries. Winfrid A. Stearns (1883) says: “Nuts, berries, and other fruits vary its fare; and to procure these it may often be seen creeping and hanging in the strangest attitudes among the terminal twigs of trees, so slender that they bend with the weight of the bird.” Audubon (1842), in his plate of the sapsucker, gives an animated picture of the bird thus engaged.