NOTES AND MEMORANDA. 117 



to the same genus of Schizophyta, and may be named "A. 

 mesenteroides." 



A structure identical in every respect with the " rrog-sj)awn" 

 of sugar factories arises spontaneously on slices of cooked beet- 

 root which are kept moist with free access of air; such culture 

 specimens differ from those of the factories only in their smaller 

 size and less density of the jelly. The jelly-balls of the " Frog- 

 spawn" consist of accumulations of jelly-masses or units, the 

 so-called " Gallertkerue." These units are naked, without enve- 

 lope ; they are close'ly adpressed one to another, or are attached 

 to one another in rows so as to form botryoidal loose or compact 

 gut-like masses. By combination of such units spherical or 

 irregularly-shaped lumps are produced, which again become com- 

 pacted into larger masses. Tbe jelly of the ultimate spheroids 

 has a varying consistence — hard, elastic, sharfdy defined, or semi- 

 fluid, with confluent outlines. It is soluble in c)ncentrated 

 potassic hydrate and in sulphuric acid; according to Durin, also 

 in ammonio-cupric hydrate. Cienkowski failed to obtain this 

 reaction, and only saw a faint blue coloration as the result of 

 this reagent. Iodine with strong sulphuric acid produces no 

 change in the jelly. 



The most important part of the ultimate spheroids are the 

 builders of the jelly — namely, the Bacteria embedded in it. In 

 young examples they are present without exception ; in older 

 lumps difficult to detect. They exhibit the most varied forms, 

 which are commonly known as Micrococcus, Torula, Bacterium- 

 chains, Bacillus, and Vibrio. The common Bacteria pass into the 

 Zoogloea condition, developing from colourless Leptothrix-like 

 filaments (see this Journal, October, 1878) by a process of 

 transverse subdivision and by the production of jelly around 

 both entire filaments and the pieces into which they subdivide, 

 and we find that the developmental history of the " Frog-spawn" 

 is simihir. Here too, as forerunners of the gelatinous growth, 

 we find colourless filaments, which are often serpentine in form. 

 The gelatinization of the Ascococcus-bnilders is easy to follow, 

 especially when they are growing on very slimy substrata. But 

 the " Frog-spawn" will also originate directly around isolated 

 Bacteria. Such gelatinous ultimate spheroids, formed indepen- 

 dently of one another come into contact with one another by 

 further growth, adhere together and form miniature examples of 

 the " Frog-spawn." The nearly aUied A. Billrothii develops 

 itself spontaneously on cooked and uncooked beet- root. The 

 jelly which envelopes the Bacteria is in this case not so copious, 

 and less refringent, than in the former species. In cultures kept 

 fairly dry A. Billrothii attains an enormous size ; it is easily 

 visible with the naked eye. It forms brown or greeni!^h heaps 



