[Ultrastructural organization of methylnitrosourea-induced brain tumors in the rat. Serial transplantation].

The specific ultrastructural features of two transplantable rat gliomas (221 and 223) are described. The tumors contained poorly differentiated anaplastic cells and differentiated cells with a great amount of gliofibrils. The resemblance of experimental gliomas to human gliomas is discussed. The capillary ultrastructure in the transplantable gliomas is described.