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some features in common, the most prominent of which is the stoppage 

 of normal growth and the substitution for it of various abortions and 

 distortions without the appearance of that rot and rapid dissolution 

 which are wont to follow on the attacks of numerous disease-pro- 

 ducing fungi and of some insects. 



I find these various maladies gradually ranging themselves in my 

 notes under the heading of Stigmonose. 



These various diseases bear another resemblance to one another in this 

 respect, that in most cases no definite organism can yet be pointed out 

 as positively the cause. All present tissue that has failed in its normal 

 functions, and, as before remarked, apparently without the interference 

 of a micro-organism such as we ordinarily find associated with such 

 appearances, say a fungus or a microbe. 



Dr. Woods, of Washington, seems to me to have done very good 

 service to pathological science in showing that the exciting causes in 

 one such case are the punctures of aphides. I refer to the well-known 

 disease of Carnations, which at one time was supposed to be of bacterial 

 origin. He has called this disease " Stigmonose," and the term might 

 be general in its application, as, I believe, he suggests. 



There are a number of small creatures that make minute punc- 

 tures in plants in the process of securing their food, not only aphides, 

 but also mosquitoes, scale-insects, small bugs, red spiders, and others, 

 not forgetting the free-living nematodes. The point seems to be that 

 the proboscides of these animals are so small and probably so well 

 sterilised by natural secretions that the wound made by their punctures 

 is not entered by any micro-organism, and yet either the irritation or 

 the chemical action of the injected animal secretions subsequently so 

 interferes with the normal growth of the tissues as to give rise to marked 

 disease, that is, to " Stigmonose." 



It is, of course, possible that these puncturing creatures in some 

 instances produce disease after the manner of the cattle-tick, i.e., by 

 the introduction of some micro-parasite, but thus far there is no 

 reliable evidence that this is the case. 



What is wanted is careful and expert observation of all small punc- 

 turing creatures, especially during the early growth of various fruits, 

 remembering that the presence of comparatively small numbers of 

 them may account for considerable damage if they are given the 

 necessary time. It is the habit of a number of these creatures to 

 puncture, suck, then pass on and repeat the operation. A single 

 individual acting in this manner would, if each puncture were 

 sufficiently irritating, produce an appreciable effect. 



It seems probable that these organisms are supplied with the means 

 of more or less sterilising the wounds they make (otherwise the result 

 might be disastrous to their food supply), and it may be that this 

 accounts for the absence of parasites in the subsequent malformations. 

 Observation is gradually assigning each of these separate maladies, 

 or varieties of Stigmonose, to its specific puncturing cause, but the 

 progress is rather slow. Among the puncturing species that are under 

 suspicion are Thrips, various Aphides, small Arachnids, and Nematodes. 

 Among the Aphides, one species has been proved by Dr. Woods to be 



