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 
way these practical men and women to accomplish their laudable 
and patriotic endeavour? A knowledge 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 Disease ” 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 
teaders 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. 
Tue UNIVERSITY, TF. E. WEIss. 
MANCHESTER, A. D. IMs. 
1sth March, 1916. W. ROBINSON. 
