1 8 BOTANICAL GAZETTE [ January 



Spirogyra Jurgensii (Ktz.). — This species was found in fruit in 

 the neck of a small pond May 4, 1906. In the same locality were 

 found vegetative filaments of S. Hantzschii and Oedoeonium, besides 



grass, rusted wire, and tin cans. The algae m 



January 



j 



present. The fruiting specimens were most abundant when the 

 temperature averaged about 12 C, and lasted about a week. No 

 fruiting specimens were found after May 25. Petit gives the con- 

 jugating season as April-May. 



Spirogyra catenaeformis (Hassall) Ktz. — This species, so far as I 

 know, has not been reported for this country, and is so placed because 

 it corresponds so closely to the descriptions in the works of Hassall 

 and Petit. The latter author gives the fruiting season as April-May, 



», wooded ponds, etc." The first 

 y 4 and the last May 22. It was 

 miles apart. One was a shallow 

 racks near a small stream. The 

 for both localities. The tempera- 

 :o 1 7 C. This species was found 

 ith S. injlata and S. calospora in 



ery 



same 



another pond. 



Spirogyra varians (Hassall) .—This plant was studied in five 



from 



In one case the water was 



rather swift and the Spirogyra was fruiting wherever it happened to 

 lodge against a support. The other localities were shallow ditches 

 and ponds. The first fruiting material was collected May 2, and 

 the last May 23. In all localities except that in swift water this 

 species fruited abundantly. The average temperature of the water 



was 8-12 C. 

 Spirogy 



' this species my observations 

 mile apart. In one S. longata 



200 



rods of surface. In both ponds the plant in question was well 

 exposed to bright sunlight, receiving its 

 ous algae which were present. The tei 



main protection from 



L ged 



from 















