and Laboratory Methods. 2531 



tion of their spores. The following is Prof. Swingle's own summary of the 

 process of spore formation in Rhizopiis and Phycotnyces : 



1. Streaming of the cytoplasm, nuclei and vacuoles up the sporangiophore 

 and out toward the periphery, forming a dense layer next the sporangium wall 

 and a less dense region in the interior, both containing nuclei. 



'1. Formation of a layer of comparatively large, round vacuoles in the denser 

 plasm parallel to its inner surface. 



3. Extension of the vacuoles by flattening, so that they fuse to form a curved 

 cleft in the denser plasm ; and, in the case of Rhizopus, the cutting upward of a 

 circular surface furrow from the base of the sporangium to meet the cleft formed 

 by these vacuoles, thus cleaving out the columella. 



4. Division of the spore-plasm into spores ; in Rhizopus, by furrows pushing 

 progressively inward from the surface and outward from the columella cleft, both 

 systems branching, curving, and intersecting to form multinucleate bits of proto- 

 plasm, surrounded only by plasma-membranes and separated by spaces filled 

 with cell sap only ; in Phycotnyces, by angles forming in certain vacuoles contain- 

 ing a stainable substance and continuing outward into the spore-plasm as furrows, 

 aided by other furrows from the columella cleft and dividing the protoplasm into 

 bits homologous with and similar to those in Rkizopus, and separated by fur- 

 rows partly filled with the contents of the vacuoles that assist in the cleavage. 



5. Formation of walls about the spores and columella, and, in the case cf 

 Rhizopiis, the secretion of intersporal slime. 



6. Partial disintegration of the nuclei in the columella. c. j. c. 



CYTOLOGY, EMBRYOLOGY, 



AND 



MICROSCOPICAL METHODS. 



AGNES M. CLAYPOLE MOODY. 



Separates of Papers and Books on Animal Biology should be sent for Review to Agnes M. Claypole 

 Moody, 125 Belvedere Street, San Francisco, Cal. 



Brues, C. T. Development of Stylopide. Zool. The author has worked on three North 

 Jahrb. 18: 241-270, 2 pis. 3fig.s, 1903. Rev. American species of Xows \ these live 

 ■ '*' ^" '^^'^ "^'^^' '^°^' as internal parasites of wasps, espe- 



cially PoUstes. The behavior of infected wasps toward the parasites is usually 

 friendly. The distribution is erratic, due probably to the difficulty of transfer of 

 parasites from one nest to another. Large numbers of larvae occur in one host, 

 which dies soon after the emergence of the male Xenos. The oogenesis is peculiar. 

 Very small larvae show strings of primitive ova on each side of the gut ; these 

 grow and later break up, giving rise to eggs, each of which consists of a mass of 

 muse-cells with a polar cap of cells divided from the primitive egg Yolk is 

 formed from the contents of each egg, and when mature, eggs are scattered 

 through the body and in the fat body. Maturation apparently occurs through 



