158 



THE YOUNG NATURALIST 



only, for it does not apply to the golden brown 

 tr&tm of the northern counties, which is the 

 form most easily confounded with Aquilina. 

 The want of resemblance of these northern 

 specimens to the published accounts of tritici, 

 led the writer at one time to send them out 

 as aquilina, and out of hundreds of specimens 

 so sent away, to experienced as well as inex- < 

 perienced collectors, not one was ever objected 

 to. Mr. Harwood. of Colchester, was the 

 first to call attention to the error, and after a 

 correspondence with Mr. Doubleday on the 

 subject, and the careful examination of a 

 great number of both species, I think I have 

 learned to discriminate between them. 

 Whether I can. in words, point out these 

 differences to others is another matter. I 

 can but try, and If I fail, I do so in good 

 company. 



In the first place aquilina is the larger 

 insect of the two. The smallest specimen I 

 have is one line larger than the largest of my 

 tritici, but on the average it is fully two lines 

 wider in expanse, This of itself should be a j 

 sufficient guide for their separation. But 1 

 this extra length of wing, gives extra width 

 at the hind margin, and makes aquilina look 

 a larger insect than it really is. Both insects 

 are similarly marked, but aquilina is very 

 much more uniform than tritici, which varies 

 exceedingly, and is found both lighter and 

 darker in hue than its near ally. To separate 

 them I would advise first that the larger 

 specimens be picked out. All that expand 

 over an inch and a quarter will be aquilina, 

 all that expand under one inch and two lines 

 will be tritici. Next separate all those that ! 

 are most strongly marked, whether it be the J 

 sub-costal streak that is distinct, the stigmata 

 that are very palely outlined, the space j 

 between them that is extra dark, or other 

 distinct marks. All these specimens will be | 

 tritici, as will those that have a grey tinge. ! 

 You will now have only a few obscurely 

 marked specimens left, most of which are 

 probably tritici, unless you live where one 

 occurs, and not the other. From those you 



have already decided you will be able by com- 

 parison to make out most, if not all, and the 

 more you examine them, the more certain 

 you will be Is to your accuracy, and you will 

 find that the larger number of specimens you 

 have, the easier will they be to separate. 



Dr. Staudinger considers aquilina to be a 

 mere variety of tritici, which he distinguishes 

 as 11 major, dilutior." Mr. Doubleday says, "I 

 think it is a good species." Mr. Buckler has 

 reared both from the larvae, which he finds 

 are different. Boisduval examined Mr. 

 Doubleday's specimens, and said they* were 

 correctly named, and those who have good 

 series of the two insects, will have little doubt 

 of their distinctness. 



THE PRIMROSE. 



( Primula vulgaris.) 



Continued from p. 150. 



By J. P. Soutter, Bishop Auckland. 



Whenever primroses and cowslips are 

 found growing together hybrids occur. These 

 are produced by the pollen of one species 

 being carried by insects to the stigma of the 

 other, the progeny partaking less or more of 

 the character of both parents. These are 

 oxlips, and are the origin of the common 

 polyanthus of the gardens. Some have main- 

 tained that primroses, oxlips, and cowslips 

 are all varieties of one species, but although 

 they have doubtless all descendad from one 

 original type, the primrose and cowslips are 

 now as well defined as any botanical species 

 can be. The best proof of that, is the pro- 

 cess of hybridisation ; although it is com- 

 paratively easy to raise oxlips by intercross- 

 ing primroses and cowslips, as it is to raise 

 mules between the ass and horse, yet the 

 oxlip has the characteristic of a hybrid in 

 that it is almost entirely sterile when 

 fertilised by its own pollen, and is only 

 partially fertile when crossed by pollen from 

 one of its parents. Although very generally 



