196 



THE AMERICAN MONTHLY 



[October, 



nature required to produce a crop 

 of microbes to induce the growth of 

 every plant under the sun. The idea 

 has received the couf de grace 

 through some recent experiments of 

 Laurent, to determine whether dias- 

 tase is a product of bacterial growth. 

 Seeds were caused to germinate in 

 Koch's gelatin and plum-juice, and 

 no trace of bacteria was found. Dias- 

 tase is a product of the growth of 

 plants ; and although bacteria are 

 very important agents, take the 

 world through, there remain a few 

 phenomena wdiich take place with- 

 out their intervention. We throw 

 out this suggestion as a hint to those 

 who need it, and their number seems 

 to be increasing. We are not sure 

 but a prevailing desire for notoriety 

 has something to do with the starting 

 of many crazy notions that find their 

 way into print. 



NOTES. 



— Dr. A. Fottinger has found chloral 

 hydrate to be a good medium for preserv- 

 ing polyzoa and the lower animals. In 

 the case of polypa, when fully expanded, 

 crystals of chloral hydrate are dropped 

 into the water, and in the course of a 

 short time the colony becomes insensible, 

 when the specimen may be placed in alco- 

 hol without any contracdon or change of 

 form. Star fishes may also be treated in 

 the same manner to advantage. The 

 chloral seems to act as a narcotic from the 

 effects of which the animals may recover. 

 — H. 



— Dr. W. Morris has also devised a new 

 mounting medium which is very easily 

 prepared. Mix equal parts of sulphur and 

 arsenic disulphide and -^-^ part of mercury 

 biniodide. This mixture is melted on a 

 piece of mica and the fumes condensed on 

 a cover-glass, and the object mounted by 

 remelting the medium on the cover-glass. 

 As we understand the process, the object 

 being thus enclosed in the new medium is 

 then protected by mounting in Canada 

 balsam in the usual way. — H. 



— Verily, there is no end of the strange 

 things that can be done. We often read 

 of them, but cannot give our readers the 

 benefit of them all. Here is one they 



may try, but we prefer not to waste any 

 plates on it ourselves. Dr. H. Vaillanes 

 has devised a photo-micrographic appa- 

 ratus, and when he finds that all parts of 

 an object are not in focus at one time, he 

 overcomes the difficulty by making two 

 or three exposures on the same plate, 

 focussing the different parts independ- 

 ently so as to get them all sharp in the 

 picture. The first question that occurs to 

 us is : Has he ever tried it ? If so, there 

 must be a great difference of opinion as 

 to what is a good photo-micrograph. — H. 



— The well-known microscopist and 

 physicist. Dr. G. Royston-Pigott, has de- 

 clared his belief in the animal nature of 

 diatoms. This is a rather surprising view 

 at this age of the world, but particularly 

 so when we consider the basis upon which 

 it rests, viz. : ' Their peculiar power 

 of movement and * * conjugation, as 

 well as their unaccountable strength of 

 movement.' These seem very uncertain 

 characteristics to distinguish between the 

 animal and vegetable kingdoms. If only 

 biologists could be satisfied with such off- 

 hand distinctions it would be an easy 

 matter to mark out the dividing line be- 

 tween protophytes and protozoa. — H. 



— Mr. E. Debes has published an in- 

 teresting article treating on the collection 

 of living diatoms in the Zeitschr. f. Mikr. 

 He says that most fresh -water species are 

 found in greatest number in the spring 

 and early summer, and again in the 

 autumn. In the early spring, at the time 

 of melting snow, as the ice disappears 

 from the ponds, the attached stipitate 

 forms such as Goinp/ioneina, JiTcridion, 

 Mclflsira, Syncdra, and Fragilcu-ia are 

 found ; later, as the water becomes warm, 

 these all disappear and give place to un- 

 attached, free species, which are those 

 almost exclusively found in the fall. — H. 



— The function of the pulsating vacu- 

 oles of infusoria has long been a subject 

 of speculation. As regards their struc- 

 ture, it is maintained by some that they 

 have definite membranous envelopes, but 

 this is denied by others, and it is now 

 generally conceded that they are mere 

 cavities in the protoplasm. M. Z. Fiszer 

 believes, with O. Schmidt, that they com- 

 municate with the exterior of the body 

 through a special exit, which allows of the 

 escape of the fluid in the vacuoles. Ac- 

 cording to this view they constitute a part 

 of a circulatory system to supply oxygen 

 from the water, and perhaps also to carry 

 off excretory products. The water taken 

 in at the mouth parts with its oxygen to 



