yo THE SAPROLEGXIACEAE 



branches, which then plainly enwrap the oogonia. Here and there 

 fertilizing tubes to be seen: conidia produced in abundance in chains 

 or rows, or racemes, with manifold side branches, also in empty sporangia; 

 many chains visible to naked eye, some 1-1.5 mm. long. 



Saprolegnia criistosa van III. p. 54. 



Found in same place as var. II. A somewhat denser turf than in 

 var. II distinguish the two nearly related species; hyphae 1.5 cm. long; 

 rather flexible, but standing out straight. Sporangia as usual. In 

 cultures on mealworms and ant larvae there occur at the beginning 

 neither the sporangia nor oogonia. Slowly the fungus strengthens itself 

 in the culture and forms the turf, which does not disappear. Oogonia 

 racemose, or also terminal or intercalary, stalks very unlike, and the 

 arrangement thus of very different appearance. They are short, or at 

 times so long as scarcely to be recognized as oogonial stalks. Oogonia 

 mostly spherical, seldom elongated, membrane of medium thickness; 

 pits numerous, small, sharply defined. Diameter of oogonia 73-121. 5[j., 

 rather regular (small ones with 1-3 eggs are rare). Hollow tubes not 

 rarely enter the oogonia from below. Eggs 20-50, wall thin, almost 

 colorless, thickness nearest that of S. dioica, being 22-291X. Antheridia 

 diclinous, only on about one-third of the oogonia. Conidia various in 

 position and form; spherical, barrel-shaped to long-compressed and thread- 

 like, often difficult to describe, enormously various in size, 30 to 300 

 or 500;x thick. Position of the conidia very various, in chains with 

 sporangia, also Avith side-branches, also sympodial or irregularly tangled, 

 and thus most resembling S. rhaetica, often in empty sporangia. Oogonia 

 may also be formed at times (not often) in empty sporangia. 



Saprolegnia stagnalis Tiesenhausen. Arch. f. Hydrobiol. und Plankton- 

 kunde 7: 276. 1912. 



Found in a ditch near St. Moritz, in Oberengadin, Switzerland. 



"Turf delicate, about 2 cm. broad, sporangia usually rather slender, 

 e. g., 260x2911., 50ox20:jL, 720X45SX, or even 8ox20ii. in size. The sec- 

 ondary through-growing sporangia are constricted {i. e., grow through 

 the older ones and are pinched in by their mouths). Oogonia 25-8otx 

 in diameter, terminal on the principal branches and on side branches, 

 sometimes on branches of the second order, also inside empty sporangia 

 or in a row by twos (zu zweien) ; wall with numerous pits that are even 

 visible in surface \-iew; stalks short and often bent. Eggs as a rule con- 

 centric, 12-22. 5tj., exceptionally 32.5xi5!j.; 1-12 in an oogonium. One 

 or two eggs in an oogonium occur frequently. Antheridia always di- 

 clinous." 



The author remarks that the species differs from 5. dioica {S. di- 

 clina) principally in four points: (i) The constricted sporangia (the 

 sporangia of S. dioica do not grow beyond the older ones). (See deBary, 

 '88, p. 619, pi. ID, fig. 13.) (2) In S. dioica the oogonia appear 

 only on the tips of the main branches, while in S. stagnalis they also 



