. Ants; their structure, development and behavior. The latter isformed by a tubular invagination of the ectoderm similar to that which FIG. 41. Larva of Ponera forms the OeSOphagUS. Owing to the pennsylvanica. (Original.) a, Larva closure between the chylific stomachand the hind-gut, all the undigestedportions of the larval food enclosed in the series of successively sloughed peritrophic membranes, accumulatein the cavity of the stomach and form a black, elliptical mass, the me-coninm, which often shows through the translucent body walls of thelarva. The hind-gut,is differentiated into two reg
. Ants; their structure, development and behavior. The latter isformed by a tubular invagination of the ectoderm similar to that which FIG. 41. Larva of Ponera forms the OeSOphagUS. Owing to the pennsylvanica. (Original.) a, Larva closure between the chylific stomachand the hind-gut, all the undigestedportions of the larval food enclosed in the series of successively sloughed peritrophic membranes, accumulatein the cavity of the stomach and form a black, elliptical mass, the me-coninm, which often shows through the translucent body walls of thelarva. The hind-gut,is differentiated into two regions, a more slender,tubular anterior portion, the small intestine, and a more capacious sac,the large intestine. The latter is constricted behind and opens on thesurface as the anus, which has the form of a transverse slit and is pro-vided with a sphincter muscle. Four Malpighian tubules open into theanterior blind end of the small intestine and describe a few convolution^in the-dorsal body cavity. In the ventral body cavity lies a pair of less. ready to pupate; b, bristle-cappedtubercle of same ; c, head fromabove. c( involuted sericteries, or spinning glands, which unite to form a duct,opening on the tip of the labiuni. These organs are also present in lar-va- that do not spin cocoons. The nervous system consists of a cerebralganglion, connected by a pair of commissures surrounding the cjesopha-gus, with the most anterior of a series of twelve ganglia, which extendthrough the body on the ventral side of the alimentary tract. The tir^t,or suboesophageal ganglion, is a fusion of the ganglia of the and labial segments of the embryo. The tubular heart liesjust under the dorsal integument and terminates anteriorly beneaththe brain. The pericardial cells float out into the body like a velum oneach side of the heart. The feebly developed muscular system con-sists of longitudinal fibres lying in two latero-dorsal and two latero- ventral zones in the various seg-
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Keywords: ., bo, bookcentury1900, bookdecade1910, booksubjectants, bookyear1910
