1883] 



MICROSCOPICAL JOURNAL. 



217 



etable world is starch. Starch is never 

 produced by animals, or at least its 

 production in the animal world must 

 be regarded as extremely doubtful. 

 It is a characteristic of vegetal life, 

 and forms an important source of 

 nutriment to the animal body, being- 

 transformed into fatty matter, and 

 consumed as fuel to maintain the tem- 

 perature. 



It is interesting to consider that, 

 according to the Uter researches of 

 K. Brandt, there is alike interdepend- 

 ence between certain lower forms of 

 animal and plant life, manifested in 

 those organisms, which, while they 

 are clearlv animals, possess granules 

 or cells containing chlorophyl. It is 

 not a new idea that the green or the 

 yellow cells of animals may be para- 

 itic plants, for it was long ago sug- 

 gested that the yellow cells found in 

 the radiolaria, as in the pol3'cystina 

 for example, and in many fresh-water 

 rhizopods also, might be unicellular 

 plants, and in support of this sup- 

 position it was observed that after 

 the death of the animals the plants 

 continued to grow. K. Brandt, how- 

 ever, has again taken up the subject 

 for investigation, and he finds that the 

 yellow cells of foraminifera, radiolaria, 

 ciliata, sponges, and also of some 

 higher animals, are algae upon which 

 the animals, especially the radiolaria, 

 at least in a measure, are dependent 

 for their nourishment. He concludes 

 that the yellow cells are resting stages 

 of certain higher algae, especially of 

 the melanophyceae. Doubtless the 

 yellow algal cells grow with unusual 

 vigor in the animal body owing to the 

 abundance of carbonic acid gas 

 evolved by the animal, while the ani- 

 mal is in turn benefited by the starch 

 produced by the alga and assimilated 

 by the animal. Starch has been 

 found free in certain collozoa, sup- 

 posed to be derived from the algal 

 cells. 



Foraminifera in Chalk. — Mr. M. 

 C. Cooke has lately recorded, in a 

 paper read before the Quekett Club, 



the results of some old but not previ- 

 ously published calculations of his 

 own, on the number of foraminifera 

 in the Kentish chalk. He took an 

 ounce of chalk from the pit and 

 removed the lighter fragments by con- 

 tinued washing, until a sediment of 

 nearly pure foraminiferal shells was 

 obtained. Half of this was cleaned 

 by boiling in caustic potash and 

 ultimately there was found enough 

 material to mount 190 slides of 1000 

 shells on each. An ounce of the 

 chalk, therefore, yielded 400,000 

 shells. In another experiment, more 

 carefully conducted, upwards of half 

 a million shells were obtained, with- 

 out reckoning fragments washed away, 

 etc. Hence the pound of chalk from 

 which the specimen was taken con- 

 tained 128,000,000 foraminiferal shells 

 — a number which it would take ten 

 years to count at the rate of sixty a 

 minute for twelve hours each day. 

 Ehrenberg calculated that there were 

 one million and a third organisms in 

 a cubic inch of chalk. This would 

 be equivalent to 288,000,000 in Mr. 

 Cooke's block, which, according to 

 his own calculation, contained 256,- 

 000,000. These two results, obtained 

 independently, indicate that they are 

 quite near the truth. If each of the 

 shells in an ounce of chalk was as 

 large as the shell of the common gar- 

 den snail. Helix asprra, they would 

 form, side by side, an unbroken line 

 12 miles in length. 



Preservation of Museum-Speci- 

 mens. — At the International Fisher- 

 ies Exhibition some fine specimens of 

 delicate marine organisms are shown, 

 preserved in spirit by a method adopt- 

 ed at the Zoological Station at Naples. 

 These specimens embrace many ani- 

 mals which it would scarcely be 

 supposed could be satisfactorily pre- 

 served. Among them are many of 

 the coelenterata almost as perfect as 

 in life. The most delicate jelly-fishes 

 are shown as clear, transparent, 

 masses of jelly floating in the liquid 



