22 



when taken young is unfailing ; but in the more advanced 

 growth, when the spores are nearly matured, ferns forming 

 no exception in Nature's laws, protect their own offspring 

 against the burning rays of the midday sun, and the 

 baneful effects of too much wet in the perfecting and 

 ripening of the spores by reflecting or folding back the 

 margins of their pinnules, which would be destroyed were 

 they to remain concave. 



In the 4th Column we come to the form of the pinnula 

 or pinnule ; in Lastrea propinqua it is obtusely biserrate and 

 biauriculate, occasionally developing the anterior auricle 

 to such an extent as to become a small attached twin- 

 pinnula. It is also succulent, soft and pulpy, very like a 

 diminutive leaf of Sedum Telephium, with its margin 

 slightly thickened. In Lastrea filix mas the pinnula is 

 scarcely auricled, indeed one may say never, except when it 

 runs into the variety of deorso-lobata of Moore. In Lastrea 

 pseudo mas the pinnula is not auricled at all, and generally 

 has a squared oblique apex, which never obtains in the 

 other two forms. 



In the 5th Column. — Difference of colour is difficult to 

 judge of at all times ; but if you will refer to the diagram, 

 you will find that attached to the different forms is again 

 rather an eye difference than one which can be expressed 

 by words. 



6th Column. — The next diagnostic I consider a very 

 good one, and which may be thoroughly relied upon, viz. 

 the state of the old fronds when a winter has passed over 

 them. Those of Lastrea propinqua are of a beautiful iufus 

 brown, and perfectly fragile and perished. Those of 

 Lastrea filix mas are of a dirty brown, with remains of the 

 green, prostrate and fragile. And those of Lastrea pseudo 

 mas are so tough that you cannot separate them from the 

 plant; and they remain, unless beaten down by a heavy 

 fall of snow, upright through the winter. They are 



