Observations on the Conjugatae. 
BY 
W. WEST, F.L.S., & G. S. WEST, A.R.C.S. 
With Plates IV and V. 
D URING a prolonged study of Freshwater Algae from 
all parts of the world, many more or less interesting 
observations concerning the Conjugatae have accumulated : 
in this paper we propose to set forth some of them, together 
with certain conclusions derived therefrom. This group of 
Algae has been extensively studied by many previous botanists, 
amongst whom particular mention may be made of De Bary, 
Wittrock, Nordstedt, Lagerheim, Klebs, Bennett, and others; 
and we have here attempted to correlate with each other and 
with our own observations, a few of the facts described by 
these several observers, and from this to ascertain, as nearly 
as possible, the relationship existing between the various 
members of the group. 
We classify the Conjugatae into the three following families : 
Zygnemaceae, Temnogametaceae, and Desmidiaceae, 
and in this paper we think it advisable to deal with them 
separately. 
Many authors regard the Mesocarpeae as a separate family, 
owing to the peculiar formation of the spores ; but we think 
[Annals of Botany, Vol. XII. No. XLV. March, 1898.] 
