120 The Microscope. 



manifests itself by the presence of knots on the roots with their 

 subsequent decay, and " the plant stops growth, the fruit either 

 becomes destroyed or drops prematurely, the leaves change color 

 and fall off, and the plants die so rapidly as to justify the usual 

 expression, ' struck by lightning,' applied to the fields of melons,, 

 cucumbers, tomatoes, and cow-peas so often badly affected by 

 the root-knot." 



The Anguillulai are strong enough to enter the stomata, or 

 breathing pores, active and strong enough to penetrate even the 

 cell walls, or to separate the cells in loosely connected tissues. 

 Once within, continues Dr Neal, they could easily pass to any 

 portion of the root, and it is not unreasonable to infer that in this 

 manner they obtain entrance in young rootlets. 



Much remains to be learned relative to their life history, and 

 if the microscopists of the southern States are in need of micro- 

 scopical work which may bring not only renown to themselves, 

 but perhaps help to the stricken plants, this seems to be an im- 

 portant field, and one that may be useful to tlie whole country 

 which looks to that part of the land for so many of the fruit& 

 which this little Anguillula is in a fair way to destroy, unless our 

 southern friends can unravel its life history, and point out a 

 remedy that shall protect the shrubs and -trees from its devasta- 

 tions. The disease, says Dr Neal, is found in wet, sand}' locations 

 along the coast of Texas, and not at all in other regions west of 

 the Mississippi River; but eastward it is progressively worse 

 until it reaches its climax in Florida, where its ability to do mis- 

 chief in gardens and groves is exceedingl}' great. 



Dr G. F. Atkinson in the Journal of the Elisha Mitchell Scientific 

 Society also publishes a noteworthy paper on this subject, detail- 

 ing more of the worm's life history and habits. Although these 

 two authors have greatly increased our knowledge of the parasite 

 there is still much to be done. The subject forms an important 

 field for investigation. Let the southern microscopists get to- 

 work. They have no time to lose. 



Acknowledgment. — To Prof V. A. Latham, Ann Arbor, Mich., 

 for a section of diseased lung to show her method of mounting. 

 — To Prof Wm. Lighton, Atchison, Kas., for a section of vegetable 

 ivory for the polariscope. — To Mr Fr. Dienelt, Loda, 111., for the 

 trachea' of a lejjidopterous larva with internal hairs arranged 



