Experimental Tumors after Nerve Section in an Insect.

Abstract

In Leucophaea maderae, a large Orthopteran, the recurrent nerve was cut at various levels. This nerve which belongs to the stomatogastric nervous system, innervates the anterior portion of the alimentary canal as well as the salivary glands and their reservoir. Within 10 days to several mos. after the operations, tumors developed in organs innervated by the recurrent nerve. Frequent sites of tumorous growth were the anterior portion of the mid-gut and the salivary reservoir. In the fore-gut and in the salivary glands, well developed tumors were relatively rare. Several types of control operations, such as allatectomy and castration in which the recurrent nerve had remained intact, did not cause the development of tumors. Some of the tumors obtained after the cutting of the recurrent nerve attained considerable sizes. Histologically they consist of layers of cells which show various degrees of abnormality. In advanced stages part of the cells break down into a debris of brown color. About 300 specimens, nymphs as well as d* and 9 adults, with exptl. tumors were studied.