Journal of Applied Microscopy. 405 



sides of the body are practically alike, differences appear later. The author 

 considers his method of determining numbers more reliable than Morpurgo's. 

 The latter made drawings, while Meek, beginning with this method, abandoned 

 it and actually counted the fibers in the squares of an eyepiece micrometer, and 

 added the totals ; in both cases sections of tissue were used. The inequality 

 of size of fibers is considered to be due to degenerative changes, caused by the 

 intra muscular " struggle for existence and survival of the fit." Exercise will 

 hasten the results of the struggle, while rest and feeding will delay it. The 

 author will soon publish a complete discussion of his results. a. m. c. 



Vernon, H. M. The Relations Between Mar- This investigation was carried on 



• ine Animal and Vegetable Life. Mitth. . ,, , , . ^, ^ r 



Zool. Stat, zu Neapil. 13: pp. 341-426. especially to determme the nature of 



1898. the cycle of changes through which 



nitrogenous material excreted into the water may undergo, and also as to the 

 effects of ceration. Chemical, physiological, and bacteriological questions were 

 introduced, and the study carried on along these lines. Larvae of the sea urchin 

 Strongylocentrotus lividus, readily obtainable from artificial fertilizations, were 

 grown in water of various kinds, and after eight days growth were killed, pre- 

 served, and microscopically examined with reference to size, in sets of fifty ; the 

 mean size of the sets from different tanks was then taken as a basis of com- 

 parison. The chemical side consisted in making determinations of the free and 

 organic or albuminoid ammonia present in the various specimens of water. The 

 method used was that of Wanklihn and Chapman, and consisted in distilling 

 half a liter of water in question and collecting it in volumes of 50 or 100 cc; 

 4 per cent, of Nestler's reagent is added, and the brown color resulting is deter- 

 mined by a standard. For the amount of ammonium chloride, after distillation 

 of 200 cc. of the 500, all free ammonia is removed, and treating with potassium 

 permanganate and distilling off 150 cc. more, the organic ammonia is separated. 

 Bacteriological tests were made on gelatin plates, careful count being kept of 

 the colonies found. It was determined that such weeds as Ulva rapidly remove 

 free ammonia, but add organic ammonia to tank water ; larvae living under these 

 conditions usually increase in size. Red weeds, as Gelidium, usually cause an 

 increase in both forms of ammonia, and as a rule are unfavorable to larval 

 growth. Filtration of the water through sand removes almost all free and two- 

 thirds of the organic ammonia and favors larval development. Keeping water 

 in the dark for three or more weeks results in the removal by bacterial action of 

 nearly all the free, and a third or more of the organic ammonia ; larvae grown 

 under these conditions are larger than usual. Ammonium chloride acts injuri- 

 ously to larval life, but potassium nitrite and nitrate have no effects. Aeration 

 has only a very slightly favorable effect on larval growth. a. m. c. 



Von Linden, M. Untersuchungen ueber die The writer has carried on the work 



Entwicklung der Zeichnung des Schmetter- ^j^j^ special reference to three points: 

 lingtluegels in der Fuppe. Zeit. f. wiss. ^ 



Zool. 65: pp. 1-50, pis. 1-3, 1898. first, as to whether the marking of the 



imago appear suddenly in the pupa, or 

 gradually ; second, as to whether there is evidence in the ontogenetic develop- 

 ment of these markings, of the phylogenetic history of the form studied ; 



