Decembeb 15, 1916] 



SCIENCE 



855 



doned by biologists, especially in cases in which 

 there was no possible excuse for it. 



Professor Grave has fortified himself against 

 confirmation of my views by assuming the 

 position that even if no reversal of the beat of 

 cilia is to be observed when my methods are 

 employed, " it seems clear that it was due to 

 the fact that the animals on which he made 

 his observations were, in every case, in a muti- 

 lated condition." I removed the shell, " and," 

 he says, " in its removal the adductor muscle 

 was cut and the visceral ganglion, which is 

 imbedded in this muscle, was necessarily 

 severely injured. Under such a condition of 

 shock normal behavior is not to be expected, 

 especially in the case of activities that may be 

 subject to nervous control." 



Here is another pure assumption, made 

 without observation, or even the opinion of 

 some one else to substantiate it. I have no 

 reason to believe that there is any element of 

 truth in it; and I have several reasons for be- 

 lieving that it is not true that cilia of the palp, 

 gill or mantle tracts are in any way under the 

 control of the nervous system (such as the 

 continued and unchanged beat on fragments 

 of any of these organs, and also on isolated 

 single cells, facts that can not be presented 

 here) . 



ISTow the action of gill and mantle cilia are 

 precisely the same in normal and in "muti- 

 lated" Pectens, and in some other lamelli- 

 branchs that open the shell valves widely, a 

 condition that I have observed very many 

 times. Why should Professor Grave not nat- 

 urally expect these cilia tracts, as well as those 

 of the palps, to behave abnormally from the 

 detachment of the end of the adductor muscle ? 

 For he must know that gills and mantle re- 

 ceive large nerve trunks from the visceral 

 ganglion, while the palps do not. The palps 

 are so situated that they can not be examined 

 without removing the shell valve, or using 

 great force to pry the valves far apart by 

 stretching the adductor muscles, and I have 

 not seen their currents otherwise. I would 

 like to ask Professor Grave if Engelmann was 

 careful not to mutilate the lamellibranch on 

 the palp of which he discovered a reversal of 

 the cilia beat? 



Finally, the cause of my mistakes in observa- 

 tion, we are told, was that when the end of the 

 adductor muscle was separated from its shell 

 attachment, the visceral ganglion " was neces- 

 sarily injured." I venture to offer the infor- 

 mation that, when one actually tries the ex- 

 periment, it will be found that a shell valve 

 may quite easily be removed from any lamelli- 

 branch without touching the visceral ganglion, 

 or any of the nerves arising from it; and that 

 to say that it is necessarily injured in the proc- 

 ess is but to add another to the list of these 

 entirely unsupported assumptions. This 

 a priori method of arriving at truth ought to 

 be even more out of place in present-day biol- 

 ogy than the employment of analogies. Very 

 likely, the use of the binocular dissecting 

 microscope, which I did not have because it was 

 not yet invented, will show that I made mis- 

 takes; but years were spent in making the ob- 

 servations before they were published, and 

 perhaps I may be pardoned for objecting to 

 their summary dismissal, in some cases with 

 a very small show of reason, and in others 

 with none at all. 



James L. Kellogg 



Williams College, 



"WiLLIAMSTOWN, MASS. 



CHLOROSIS OF PINEAPPLES INDUCED BY 

 MANGANESE AND CARBONATE OF LIME 



It has been recently found by M. O. John- 

 son at the Hawaiian Experiment Station that 

 the chlorosis of pineapples occurring on highly 

 manganiferous soils can be cured by spraying 

 the leaves with ferrous sulphate. 1 As the 

 chlorosis of pineapples growing on strongly 

 calcareous soils in Porto Pico can also be 

 cured by the application of iron salts, some 

 have the idea that the two forms of chlorosis 

 are the same. Although the phenomena are 

 remarkably similar in many respects, and al- 

 though the cure is the same, it is not yet 

 clear that they are identical. It seems ad- 

 visable to point out certain differences that 

 seem to exist in the two kinds of chlorosis. 



i The Pacific Commercial Advertiser, Honolulu, 

 Hawaii, July 21, 1916, and a personal communica- 

 tion. 



