8 BROOKLYN BOTANIC GARDEN MEMOIRS 



longer than broad, presenting the appearance of rods, deeply stained, 

 lying in a peripheral zone of the cytoplasm. 



The material on which this cytological study was made was not 

 as well fixed as it might have been. The peridium of the fruit bodies 

 is very dense and tough, not permitting the rapid penetration of the 

 fixing fluids. Then in the later stages of zygote formation the thick 

 cartilaginous wall of the resting zygote very likely offers great resist- 

 ance to the penetration of the fluids. An attempt will be made 

 to collect more material during the present season, when the fruit 

 bodies will be cut open before placing them in the fixing solutions, 

 and also it is hoped that younger stages of development may be 

 secured. 



Up to the present time no 'one has succeeded in germinating the 

 resting zygotes of any species of Endogone. Link (1809), Fischer 

 (1897, p. 121, 124) and Bucholtz (1912) have described sporulation 

 in the "resting spores" (azygotes) of Ejidogone pisiformis, a partheno- 

 genetic species. In this species the wall of the resting spore is only 

 slightly thickened. According to Fischer and Bucholtz the content 

 of the resting spore is gradually divided into angular areas which 

 round up and form a number of large elliptical spores inside the wall 

 of the resting spore (or ? sporangium). Their study was not made on 

 living material, but on specimens preserved for several years. There 

 was no intersporal substance or epiplasm. 



I have made several attempts to germinate the resting zygotes of 

 Endogone sphagnophila, but thus far without success. The first 

 attempts were made in December, 1916, with material kept on sphag- 

 num under cover of a bell jar in the shade on the north side of a 

 building. The cultures were made by tearing out mats of mycelium 

 with the resting zygotes in a thin layer of water on glass slides which 

 were kept in moist chambers. The cultures were examined day by 

 day for a period of two weeks. These cultures were then allowed to 

 remain out of doors on a window ledge with a southern exposure until 

 the middle of January, 1917, when they were brought inside and again 

 examined daily for a period of a week. During the latter part of 

 March and early in April, 191 7, fresh cultures were started from the 

 same source, i. e., from fruit bodies kept on sphagnum out of doors, 

 where they were subject to freezing and thaw. Thus far (Apr. 17, 

 1917) there has been no evidence of germination, although the great 

 majority of the zygotes appear to be alive and in good condition. 

 A few of the zygotes, however, appear to be dead. In many of these 

 the content is divided into irregular bodies. Others are filled with 

 elliptical or globose bodies, in some instances with intersporal sub- 

 stance. These bodies, some of them, at least appear to be spores, 



