Australian freshwater flagellates

Abstract

(Plates i. to ix.; and three Text-figures.) In the present paper I have endeavoured to give some account of all those forms of microscopic life found in our waters, which are included under the class Fhigellatae of the freshwater Algae. From the early days of my studies I have always felt a lively interest in the freshwater flagellates and looked forward to a time when I should be in a position to set forth some small attempt at a monograph 'f such as occur locally. The following notes therefore, dealing with almost a), the commonly occurring species and with a large number of forms, also, w'lieh are not at all common, represent the gleanings of 15 years. The moi'e important part of the work, however, was accomplished during the period .en, as a science research scholar of the University of Sydney, I was enabled to devote myself for some years to a more thorough investigation of Australian pond life than 1 had previously dune. It is with pleasure, therefore, that I here express my heartiest gratitude to the Senate of the University for afforded me the opportunities which have resulted in my bringing a long-cherished desire to a successful issue. In conjunction with these notes should be taken my earlier paper on "The Genus Trachelomonas.'' (These Proceedings, xl., 1915) which was written in advance, on account of the verj' large number of new forms observed in that genus. The title "Australian Flagellates" may perhaps be considered too grand when it is obser\'ed that all the gathering's were made in two localities only, viz. :-the suburbs of Sydney and the neighbourhood of Lismore. This, however, is not so, for the Flagellates are entirely cosmopolitan and the ordinary forms always very widespread. In moving from one district to another one merely picks up the same common form ov«r and over again. The rarer varieties, on the other hand, are generally polymorpliic forms without any local attachment whatever, but merely the result of unusual combinations of rain and shine, temperature , movement and stagnation in their habitat. It is for tliis reason that they are uncommon. They are entirely the product of their environment. In a very large number of cases also, they are simply stages of growth which have become fixed at that point either by the induration of the cell-wall or by the lack of any stimulus to further growth.