At the heart of these tumors, female nematodes suck the juice from grotesque, multinucleate “giant cells”.

The cytology of zygospore-formation is not known in detail; the so-called gametes which fuse are multinucleate and are no doubt of the nature of gametangia.

The trophozoite begins life as a small, rounded uninucleate corpuscle, which as it grows, becomes multinucleate.