496 HOMES WITHOUT HANDS. 



sticks, and in these spots the Sparrow loves to place its nest. 

 Mr. F. Keyl has told me that he has repeatedly seen the Storks 

 and Sparrows thus living in amity together, the stork appearing 

 to extend to a weaker bird that protection which it receives from 

 mankind. 



We now pass to the Parasitic Insects. As this work is intend- 

 ed to describe dwellings which are in some way formed by the 

 creatures, it is necessary to exclude all the parasite insects that 

 may exist upon the animal, and make no habitation, such as the 

 ticks, as well as those which are merely parasitic within the ani- 

 mal, such as the various entozoa. 



Of Parasitic Insects, the greater number belong to that group 

 of hymenoptera which is called Ichneumonidse, and which em- 

 braces a number of species equal to all the other groups of the 

 same order. Being desirous of producing, as far as possible, those 

 examples of insects which have not been figured, I have selected 

 for illustration several specimens which are now in the British 

 Museum, one or two of which have only been recently placed in 

 that collection. 



The best known of all the Ichneumonidas is that tiny creature 

 called Microgaster glomerulus, of which a casual mention has al- 

 ready been made in page 289. 



A group of these insects and their cells is now before me, and 

 will be briefly described. 



The insects themselves much resemble in general form the Bur- 

 net Ichneumon, which is mentioned on pp. 290, 292, but are 

 smaller, blacker, and not nearly so beautiful, although their wings 

 gleam with an iridescence nearly as brilliant. Small as it is, this 

 tiny insect is extremely valuable to us, and to the gardener is 

 beyond all value, though, as a general rule, the gardener knows 

 nothing about it. Were it not for this ichneumon, we should 

 scarcely have a cabbage or a cauliflower in the garden ; for the 

 noisome cabbage caterpillars would destroy every leaf of the pres- 

 ent plant, and nip the growth of every bud which gave promise 

 for the future. 



Every one knows the peculiarly offensive caterpillars which 

 eat the cabbages, and which are the offspring of the common 

 large white butterfly. In the spring the butterflies may be seen 

 flitting about the gardens, settling on the cabbages for a few mo- 



