836 



SCIENCE 



[N. S. Vol. XXXII. No. 832 



the University of Chicago, president of the 

 American Association for the Advancement of 

 Science. 



DISCUSSION AND CORRESPONDENCE 



THE EFFECTS OF PARASITIC CASTRATION IX INSECTS 



In his very interesting paper on the above 

 subject published in the Journal of Experi- 

 mental Zoology, for July, 1910, Professor W. 

 M. Wheeler says (p. 419) that " Giard has 

 given good reasons for supposing " that the 

 dimorphism exhibited by the forcipes of male 

 earwigs from the Fame Islands, Northumber- 

 land,' is due to " diilerences in the number of 

 gregarines they harbor in their alimentary 

 tract." The reference to Giard is Oomptes 

 Bendus Acad. Sci., 1894, Vol. 118, p. 872. 



J'ai tout lieu de croire qu'une interprStation 

 du meme genre (referring to the changes brought 

 about in Carcinus by the action of parasites) peut 

 s'appliquer pour la distribution des longueurs des 

 pinces des Forficules males. II est possible, en 

 effet, d'aprfes la longueur de la pince, de prgvoir 

 qu'une Forficule male possgde des Grfigarines et 

 qu'elle en possSde une plus ou moins grande 

 quantity. 



We do not, however, feel justified in regard- 

 ing this passage alone (and there is no further 

 account by the French observer) as direct evi- 

 dence that Giard had examined the intestine 

 of Porficula for gregarines and found a corre- 

 spondence between their presence and the dif- 

 fering states of the male secondary sexual 

 characters. In this connection we may record 

 our own observations made to resolve this de- 

 batable point. In 1907 we visited the Fame 

 Islands and collected several thousand ear- 

 wigs. Over fifty dimorphic males were care- 

 fully dissected and a large gregarine (pre- 

 sumably Gregarina ovaia) was found to occur 

 commonly in the alimentary canal. Examples 

 were, however, contained indifferently in low 

 males as well as high ; in both they were some- 

 times absent and no correlation could be ob- 

 served between the number of parasites in an 

 individual and the length of its forceps. It 

 may at the same time be mentioned that no 



^ Bateson and Brindley, Proc. Zool. Soc. London, 

 1892, p. 585. 



difference in the development of the testes or 

 other internal sexual organs could be detected 

 in high and low males respectively. 



H. H. Brindley 

 r. A. Potts 

 Zoological Labobatoet, 

 Univeesitt of Cambbidge, 

 October 20, 1910 



mono- and DI-BASIC PHOSPHATES 



Recently my attention has been directed 

 to the confusion in the use of the terms 

 " mono- " and " dibasic " as applied to the 

 alkali salts of orthophosphoric acid. As cer- 

 tain authors make use of these terms without 

 further qualification, it seems desirable to call 

 attention to the conilicting use of these terms 

 and to urge instead the use of more precise 

 designations. 



Orthophosphoric acid, HjPO,, is generally 

 considered to be a tribasie acid. As salts of 

 this acid, it seems only logical to call KIIPO^ 

 dibasic, and K,IIPO^ monobasic. In Merck's 

 and some other catalogues, KHJOj is called 

 monobasic, and K.HPO, dibasic. These firms 

 commonly send out their preparations labeled 

 as follows : " Potassium phosphate— Dibasic," 

 and " Potassium phosphate — Monobasic." 



No further explanation appears on the label, 

 and unless one happens to consult the cata- 

 logue (and this does not always explain) 

 one is apt to get curious results in the use of 

 these salts. The more serious difficulty ap- 

 pears, however, in the use — without other 

 qualification — of the terms " mono- " and 

 " di-basic phosphate " in literature. This is 

 frequently the case in physiological and bac- 

 teriological papers. In discussion of the mat- 

 ter with a number of technical chemists it 

 was evident that the conflicting use of these 

 terms was not confined to biologists. 



In view of the confusion resulting from the 

 uncertain use of the terms " mono- " and 

 " di-basic " as applied to the alkali phosphates, 

 I would urge all workers — and chemical supply 

 houses — to discontinue the use of these terms 

 and to substitute more exact terms, such as 

 primary, secondary and tertiary, respectively, 

 for the salts KH;P0„ KHPO,, K3PO,. It 



