PREFACE. 



The course of lectures of which this little book is a summary 

 was undertaken with a view to giving some assistance to those 

 who were endeavouring, to the best of their ability, during the 

 present crisis to increase the productiveness of their gardens or 

 allotments. Was it possible for the University to aid in any 

 w'ay these practical men and women to accomplish their laudable 

 and patriotic endeavour ? A know ledge of the structure and 

 life of the plants they cultivate could not fail to be helpful to 

 gardeners and allotment-holders in explaining the reasons for 

 many of the common horticultural practices. Familiarity also 

 with the common animal and fungal parasites of our garden 

 crops, and the methods of combating these pests would enable 

 them to save many doomed plants. For these reasons this course 

 of lectures on " Plants in Health and Diseiase " was instituted, 

 and, as the size of the audience indicated that the lectures met 

 a real need, it seemed desirable to issue to members of the 

 audience a short eight-page summary of each of the lectures. 

 As we have received many enquiries from persons not attend- 

 ing the lectures both for single abstracts, and since the con- 

 clusion of the course, for complete sets, we have decided to 

 reprint them in book form. We trust, however, that the fact 

 will not be overlooked that this issue does not pretend to be 

 more than a somewhat brief summary of a course of lectures, 

 and that all the lecturers were tied down to very narrow limits 

 wherein to compress the subject matter of a much longer dis- 

 course. We would also point out that, as the lectures were 

 addressed to a Manchester audience, the lecturers often dealt 

 with the peculiar difficulties that are met with in this neighbour- 

 hood, and that the accounts given of the animal and fungal pests 

 do not profess to be exhaustive, but are descriptive of the more 

 common diseases occurring in the gardens and allotments in the 

 vicinity of our large industrial towns. The necessary condensa- 

 tion of many interesting points, which might with advantage 

 have been expanded, and the omission of the illustrations which 

 accompanied the lectures, will probably be less noticeable to 

 those who have attended the course of lectures than to new- 

 readers of this little volume; nevertheless, we hope that these 

 latter will also find in it some information, which may be of 

 value to them. Should this hope be realised we shall feel well 

 satisfied. 



THE UNIVERSITY, F. E. WEISS. 



MANCHESTER, A. D. IMMS. 



March, igi6. W. ROBINSON; 



356869 



