SAPROLFGXIA 35 



thinking the normal eggs eccentric. His figures clearly show eccentric 

 eggs, but nia>- they not Iia\-c been l)rcaking down? Tliis seems the 

 more likely as no other Saprolcgnia has an eccentric egg. Moreover, 

 deBary found his plant only once (in a small swamp at Strassbourg) 

 and had it in cultivation only two months before losing it. He grew 

 cultures from a single large spore and found them to produce both large 

 and small spores. Our pure cultures were made from single spores, 

 but whether large or small was unfortunately not noted. They pro- 

 duced both oogonia and antheridia, as described above. This proves 

 that at leastoneof the two sorts of spores is bisexual. Fischer ('92, p. 337) 

 suggests that the small spores may be male (and, by implication, the 

 large ones female). 



Since deBary's day no one seems to have found the plant except 

 Obel, who casually refers to it in his paper on oogonia formation in AcJilya 

 decorata (Ann. Mycologici 8: ^22. 1910), saying that "Cultures of this 

 species grown up from the great [larger] zoospores may be low and crowded 

 with oogonia, while cultures grown up from old gemmae may be large 

 and quite free from oogonia generation after generation." He does 

 not further enlighten us on the important point as to whether the cul- 

 tures from gemmae ever do form oogonia. 



This species is apparently nearest 5. diclina, as indicated by the 

 strictly diclinous antheridia on every oogonium, the unpitted wall of 

 the oogonia, and the apical or intercalary position of the oogonia. It 

 differs from that species in the spores of two or more sizes, in the smaller, 

 more spherical oogonia (apical oogonia of 5. diclina are mostly oval), 

 with fewer eggs, which are abundantly borne at room temperature, in 

 the more conspicuous antheridial branches which do not disappear so 

 quickly, in the large and tuberous antheridia, and in the absence of the 

 abundant long gemmae of S. diclina. Saprolegnia Kaiiffmaniana differs 

 in about the same respects. 



In the appearance of the culture, the abundance and size of the 

 oogonia and in number of eggs the species is like 5. delica, but is easily 

 distinguished from it by the unpitted oogonial walls, the many inter- 

 calary oogonia, and by constantly diclinous antheridia. In the several 

 collections that we have measured the oogonia of S. anisospora average 

 about \ to Y^ larger than in 5. delica on the same medium. 



A rather frequent abnormality is that shown in the oogonium on pi. 9, 

 fig. 8. The protoplasm, instead of dividing into several eggs, rounds 

 itself up into a single dense mass, the size of the combined eggs of a 

 normal oogonium, the mass remaining homogeneous, as in a gemma, 

 but denser, and not taking on the centric structure of a normal egg. 

 Such masses might be considered as modified gemmae rather than eggs. 



