1891.] MICROSCOPICAL JOURNAL. 245 



of fact." He thus ascribes the motion of the "wheels" or Limnias 

 for that of Hydra. He then figures and describes Cyclops quadri- 

 cornis., and says they " all are breeders, and carry spawn at their tayl, 

 that of Fig. 5, in two bags (one on each side) , which are fastened about 

 the fifth joint, and the other in a single bag or film under the tayl, and 

 I have often seen these bags broken and the spawn (which is globular 

 and large in proportion to the fish) scattered through the water." 



In his letter of July 5, 1703, he described but does not figure Volvox 

 giobator. He say that " each of these spherical bodies (which are 

 smaller than a mustard seed) have a constant progressive motion, and 

 at the same time a slow revolution about their own axe, and contain 

 within them other small globules, some more, some less, but I never 

 found above 10 in any one, and these I have seen move and change their 

 position within the other, which Mr. L. says he has never observed." 



In his letter of July 5, 1703, he says: " In my observations of these 

 stalks I often saw adhering to them (and sometimes separate in the 

 water) many pretty branches, composed of rectangular oblongs and 

 exact squares which were joyn'd together, as you may see in Fig. VII, 

 which I drew exactly as I could from one of them. There are often 

 twentv or more of these figures in one branch, which generally adheres 

 at one end to the stalk of the plant, and I think it remarkable that these 

 rectangular parallelograms are all of the same size, the longest side not 

 exceeds \ of an hair's breadth, and that the length is just double the 

 bi'eadth, the squares being visibly made up of two parallelograms joyn'd 

 longwise. They seem very thin, and the texture of every one is nearly 

 the same. To a very large magnifier they appear as in Fig. VIII. I 

 took these branches at first for salts, but finding them always of the same 

 size, and that there was no sensible increase in their bulk while they 

 continued in the water, that after they had lain a day or two dry on a 

 glass plate they altered not their figure, and upon the addition of new 

 water (warm or cold) they had still the same appearance and cohesion, 

 and that their adherence (though touching only at the angular points) 

 was so firm and rigid that they moved together, and kept the same po- 

 sition in respect to one another, liowever agitated by the water ; these 

 considerations, I say, persuade me that they may be rather plants than 

 salts, but they being so very minute that no judgment can be made of 

 'em but by the eye, I shall not determine anything positively." These 

 were a diatom, Tabellaria Jloculosa. Thus in Vol. 23 of the Phil- 

 osophical Transactions for the years 1702 and 1703 (published in 1704) 

 we have the first discoveries of diatoms. 



Dispora Caucasica. — From No. 16 of "Contributions from the 

 Cryptogamic Laboratory of Harvard University " we learn that 

 " Kephir," which is used in the Caucasus Mountains to ; roduce an 

 alcoholic fermentation in milk, has been discovered in tl.is country', 

 specimens having been sent to the laboratory from New Jersey and 

 from Ontario. In the Caucasus the Kephir grains are said to grow in 

 little clumps or granules on peculiar bushes found on the mountains 

 just beneath the snow line. The grains are composed of yeast cells 

 and bacteria embedded in a zoogloea mass. Edouard Kern published 

 the first account of the Caucasian " Kephir" in 1881, and gave the 

 bacterium the name of Dispora Caucasica. 



