202 



THE AMERICAN MONTHLY 



[November, 



action of this water. Without having 

 known of their work I used Javelle 

 water in the preparation of spongillae. 



If silicious sponges are burned or 

 heated in alkali . solution the hard 

 parts, spicules, amphidisks etc., fall 

 apart and cannot be prepared in their 

 natural position. In order to obtain 

 them in their natural position in the 

 most convenient way, a portion of 

 the sponge is placed on a slide, co- 

 vered with a few drops of Javelle 

 water and allowed to stand protected 

 by a watch-glass until all the soft 

 parts are dissolved, which may be in 

 20-30 minutes with thin pieces. 

 Gemmules require a longer time, per- 

 haps over night, and their contents 

 an dissolved without destruction of 

 the outer membrane. 



When all the protoplasm is dis- 

 solved the preparation is treated with 

 acetic acid, which removes all ob- 

 scuring precipitates, then washed 

 with dilute, and finally with absolute 

 alcohol, after which oil of cloves will 

 clear all the still dull-looking gemmu- 

 les andCanada balsam can be used for 

 mounting. The gemmules of Spon- 

 gilla fluviatilis, Lieberkiihnia and con- 

 tecta, and of such specimens as grow 

 spread out flat on the under sides of 

 stones, are obtained in situ among the 

 spicules, and give with these a com- 

 plete picture of the form of the 

 sponge. In thicker sponges, as the 

 free growing specimens of Sp. Lieber- 

 kiihnia, the needles remain united al- 

 though the superficial and cement- 

 ing substance is dissolved. The 

 layer beneath behaves differently; 

 like the covering of the gemmules it 

 is not destroyed, but it does not be- 

 come colored black with nitrate of 

 silver like the latter. 



Sponges often contain diatoms in 

 their substance. These also are pre- 

 pared with the sponges as clean as 

 by burning or by boiling in acid. 

 The appearance of the frustules in 

 the Canada balsam is such that I 

 believe the Javelle water would be a 

 very useful reagent for the prepara- 

 tion of diatoms. 



Animal and Vegetable Chloro- 

 phyll. 



The Editor of the Botanical Gazette 

 writes as follows concerning this sub- 

 ject : " To say that one difference 

 between plants and animals is that 

 the food of the former is inorganic 

 and that of the latter organic is 

 hardly a correct statement, for the 

 food of both kinds of organisms is 

 necessarily organic, and its consump- 

 tion in both cases is attended by a 

 true respiration. A better statement 

 would be that plants, in general, have 

 the power of making their own food, 

 while animals, in general, do not. 

 We recognize that the agent in this 

 case is the granule of protoplasm co- 

 lored by chlorophyll, just as in the 

 consumption of the prepared food 

 the activity is vested in uncolored 

 protoplasm. The presence, therefore, 

 of chlorophyll granules lies at the 

 very basis of the distinction between 

 plants and animals. It is generally 

 stated that this does not hold uni- 

 versally, as the fungi are devoid of 

 chlorophyll and some animals are 

 known to possess it. The question 

 has now arisen, whether the so-called 

 animal chlorophyll is the same as 

 that of the plant. ■ The results of 

 some investigations upon this subject 

 are given by K. Brandt in the Popular 

 Science Monthly for October. The 

 investigations seem to show that, mor- 

 phologically, the animal chlorophyll 

 is by no means the same as that of the 

 plant for the green bodies which ap- 

 pear in some animals are themselves 

 cells rather than cell-contents, and are 

 nothing else than unicellular plants 

 which have immigrated to animal 

 bodies. They are both morphologically 

 and physiologically distinct from their 

 hosts, for they can live when separa- 

 ted from them and form starch in the 

 sunlight. Thus the distinction is 

 based on the same principle as be- 

 fore, namely, the power of originating, 

 for now we can say not only that 

 plants make their own food and ani- 

 mals do not, but also that plants make 

 their own chlorophyll while animals 



