There are many points of interest connected with the study of the 

 early life history of nematodes which would delight the embryologists, 

 but it was not our purpose to enter into this matter as it has no 

 important economic bearing and does not fall within the sphere of 

 station work. Our innumerable cultures of nematodes have furnished 

 us with rare and abundant material for such investigation, but we 

 have preferred to leave it to those especially practiced along the 

 lines of modern zoological technique. 



Our endeavor has been to acquaint ourselves with the main zoolog- 

 ical features connected with the subject as far as possible and neces- 

 sary, by careful examination of the most important literature relat- 

 ing to the subject as well as by actual research. In stating our 

 results and drawing conclusions we have endeavored to present 

 nothing which is not well established on fact and in principle. We 

 have made no attempt to present a technical treatise upon the sub- 

 ject, but have aimed to give simply a clear and concise description 

 of the nature of nematode worms and their relation to greenhouse 

 plants, together with what we have been able to learn concerning 

 means and methods for their suppression. 



This investigation has been carried on in connection with the reg- 

 ular botanical work during portions of 1894, 1895, 1896 and 1897. 

 That portion of the work relating to the life history and development 

 of the nematode has been done by Mr. Smith while the investiga- 

 tions of the remedies to be used have been carried on by Mr. Stone. 

 We have worked in co-operation with each other, however, and hold 

 ourselves individually responsible for the entire work. 



Nematode Worms in the Greenhouse. 



The practice of growing plants under glass has seen many and 

 important changes since its introduction. Beginning no doubt with 

 the growing of a few plants in the window for the sake of their 

 beauty in the winter, a comparatively short time has seen the intro- 

 duction and development of the modern greenhouse, with all its 

 accessories, improved methods, and appliances for growing plants, 

 not to mention the great development in the nature and variety of 

 the plants themselves. Especially recent is the practice of growing 

 vegetables under glass, now carried on so extensively in the vicinity 

 of all large towns and cities. During the last decade the value of 

 greenhouse products in Massachusetts has more than doubled. In 



