MANURING IN THEORY AND PRACTICE. 



347 



Aphides. These insects deposit their pupa on the 

 upper side of the Rose-leaf, mostly among the 

 Aphides. It is nearly round in shape, and after a 

 time the colour and form of the insect may he seen 

 through. No sooner are they hatched than the 

 larvae feed on the Aphides to the right and left of 

 them, and speedily reduce their numbers. On no 

 account should a Lady-bird be destroyed under any 

 circumstances, as they are wisely set to break and 

 reduce the power of vegetable-eating insects. 



What are called the Ichneumon flies deposit their 

 eggs on or just under the skin of other caterpillars, 

 the larvae, when hatched, consuming their juices 

 and sending them into a galloping consumption. 



Fig. 55.— Golden Eyes ; 2, eggs. 



But space will only permit of one more counter- 

 acting insect being noted here. But this is a host in 

 itself, and is popularly known as the Golden Eye 

 {Chrysopa perla). (See Fig. 55.) It is one of the most 

 beautiful of all insects, and, alas ! it has an odour as 

 bad or worse than that of house bugs. As it is need- 

 ful, however, for Rosarians to know their friends at 

 sight, and so spare them, it will be useful to wind 

 up our dreary catalogue of insect enemies with a 

 veritable friend. It is a nocturnal insect, and flies 

 somewhat slowly, thus being more easily captured 

 than most of those that ought to be dQstroyed. 

 It belongs to the great family of Lace-flies, the 

 name being derived from the reticulated character 

 of its wings. It is a long, delicate-looking insect, 

 unlike any other, excepting some belonging to the 

 same family and performing equally useful func- 

 tions. The eggs are placed on the tips of hairs of a 

 semi-glutinous character, arranged in something of 

 the form of a fan, a dozen or so of such hairs forming 



a nest; these hairs are first formed by the insect, 

 and the eggs placed on the tops of them. So soon 

 as hatched, the tiny larvae fall or crawl down the 

 threads, and fall foul of the Aphides and devour 

 them with amazing rapidity. It is said that the 

 insect forms its elevated nest only in the middle 

 of the Aphides already doomed to destruction; 

 and assuredly its eyes, which sparkle like jewels, 

 and hence its name of Golden Eye, are sufficiently 

 bright to take in the entire situation and act^ 

 accordingly. 



Aided by these and other insects, assisted by 

 several beetles, wasps, and flies, hosts of birds, 

 sudden and severe alternations of temperature that 

 destroy myriads of insect pests in a few hours ; by 

 the mastery of man over nature, and a destructive, 

 protective, and cultural skill, the rich heritage of 

 the ages of the past as well as the latest know- 

 ledge of the present, it is hoped that all Rosarians 

 will at least be able to keep their Roses healthy and 

 clean, if they cannot quite grow them to the highest 

 perfection. 



MANUEING IN THEOEY AND 

 PEACTICE. 



By John J. Willis. 



COMPOSITION AND EFFECT OF MANURES. 



WHAT constituents does a manure contain ? This 

 is the first and most important question the che- 

 mist has to answer before he can furnish distinct infor- 

 mation to the inquiries of the practical horticulturist. 

 How does the manure operate ? How quickly does 

 it act ? How long does its action continue ? What 

 is its worth ? Manure operates only by means of 

 the chemical substances it contains ; these must be 

 accurately ascertained before any exact data can be 

 afforded respecting it. Were this all, the study of 

 manures would be of easy application ; for chemistry 

 is now so far advanced as to be able to detect and 

 define these elements even to the most minute parts. 

 But of what use is it to the gardener to be informed 

 that such or such a quantity of potash, nitrogen, 

 phosphorus, lime, &c., is contained in a manure, if 

 he is not told at the same time how these substances 

 operate, and what is their practical value ? 



The following classification of manures, according 

 to their ingredients and effects, may be of service to 

 the gardener as a general indication of their value : — 



1. — Manures Rich in Nitrogen. 

 («) Substances containwg Ammonia or Nitric Acid 

 (Very rapid forcers). 

 Ammonium salts, nitrate of soda, nitrate of potash 

 (saltpetre), guano, soot, gas-liquor, putrid animal 



