May 13, 1921] 



SCIENCE 



453 



bryozoa colonies are usually complete, unless 

 broken during dredging operations. 



The bryozoan individual is always small, 

 being rarely half as large as a pin head, but 

 the colonial mass is often of sufficient size 

 to render them desirable as food for numerous 

 organisms, were it not for the fact that in 

 nearly all cases they are well protected by 

 heavy chitinous or calcareous walls. Only 

 those animals provided with strong incisorial 

 teeth or which can swallow the colony whole, 

 can utilize them. Predaceous worms and 

 other invertebrates probably are unable to 

 feed on them to any extent, for in addition 

 to its shell, the bryozoan is so highly irritable 

 to tactile stimuli that it retracts into its shell 

 with great rapidity at the slightest touch. 

 Possibly some of the softer-bodied ctenostomes 

 may serve as food for other invertebrates, but 

 observations on this point are apparently 

 lacking. 



It should be added that the statoblasts of 

 the freshwater bryozoa are often eaten by 

 young fishes. During a survey of the fishes 

 of Ohio, made during the past summer, stato- 

 blasts of Pectinatella and Plumatella were 

 found among the stomach contents of the 

 young of the large-mouth black bass, Microp- 

 ierus salmoides, the crappie, Pomoxis annu- 

 laris, the blue-gill sunfish, Lepomis pallidus 

 and the gizzard shad, Dorosoma cepedianum. 

 That these were picked up for food among 

 other organisms of the same size there can 

 be little doubt. 



Eaymond C. Osburn 



Ohio State TJniveksity 



COPPER IN ANIMALS AND PLANTS 



In a recent number of The Journal of Bio- 

 logical Chemistry (Vol. 44, pp. 99-112, Oct., 

 1920) W. C. Eose and M. Bodansky report 

 the finding of copper in various marine or- 

 ganisms, including Coelenterates, Mollusca, 

 Crustacea, Elasmobranchs, and Teleostomi. 

 As some of the writer's work bears on this 

 subject, the following note is offered. 



In some recent investigations on the res- 

 piration of insects the writer incinerated both 

 the blood and entire specimens of over 30 



species of insects, representing the chief 

 orders. The ash was analyzed for copper, on 

 the supposition that the copper present serves 

 as the nucleus of a respiratory pigment, 

 namely hemocyanin. In every case the ash 

 reacted positively for copper with several re- 

 agents. The amount of copper present in in- 

 sect blood is nearly proportionate to that pres- 

 ent in crayfish blood, which was used as a 

 control. 



In addition to insects and crayfish, other 

 Arthropods were incinerated, including sev- 

 eral species of plankton Crustacea, spiders, 

 daddy long-legs, and centipeds. In all eases 

 copper was found. As representatives of 

 other phyla Volvox, Lumhricus, Ascaris, 

 snails and slugs, and the blood of garter 

 snakes and human blood were incinerated. 

 Of these all but the vertebrate blood reacted 

 positively to tests for copper. As a matter of 

 fact, the snake blood also appeared to show 

 a minute trace of copper, but as the reaction 

 developed with only one of the reagents used, 

 and then only after several hours under alco- 

 hol vapor, this particular experiment is incon- 

 clusive. 



The foregoing results indicate that the ele- 

 ment copper has a wider distribution in living 

 organisms than heretofore accepted. Its func- 

 tion has been definitely determined only for 

 mollusks and Crustacea, where it forms the 

 nucleus of a respiratory protein. Its presence 

 in other Arthropods is explained on the same 

 basis, that is, in all Arthropods copper forms 

 the nucleus of hemocyanin. This is all the 

 more probable, since, as already stated, the 

 amounts present in insect blood, spiders and 

 centipeds are proportionate to the amounts 

 present in the crayfish blood used as a control. 



In considering the source of the copper the 

 writer analyzed the water of a creek from 

 which most of his aquatic material was taken, 

 and found distinct traces of the metal. The 

 water as a source of copper is of importance 

 to aquatic animals. It was shown, however, 

 that terrestrial insects, including such highly 

 specialized families as bees, ants and wasps, 

 contained copper. These and other terrestrial 

 insects, especially the herbivores, could derive 



