i6o CONCLUSION. 



the result is that every frond, since produced, has been nearly simple, or so slightly 

 indented in its edges, that, if plucked, it would almost certainly be taken for an ivy- 

 leaf by any one not well acquainted with the venation of ferns. While this book, too, 

 has been passing through the press, a friend, lately arrived in the Colony, lent me a 

 very recent work on the European ferns, from which I learned that several kinds 

 formerly considered as distinct plants are now recognised as hybrids. I have also, 

 through the kindness of friends, been enabled to peruse the writings of Thome and 

 Sachs, the great French and German botanical physiologists, which record the most 

 recent discoveries as to the reproduction of ferns. From them I learn that since the 

 discovery, in 1844, that the sexual organs of Cryptogams were situated on the 

 prothalli, the subjeft has been followed up, and still more wonderful discoveries have 

 been made. It is found that pollen plays no part in the reproduction of such plants. 

 When a pollen-grain comes in contadl with an appropriate female orgair, it is at once 

 excited by the viscid moisture of the latter, and begins to grow. It sends out one or 

 more slender filaments which penetrate the substance of the female organ till they 

 reach the ovule or life-germ of the future fruit. They seize upon this, apparently 

 piercing it and stirring its contents, and so causing the growth and development of 

 the fruit. Nothing of the kind occurs in the case of cryptogams. A prothallus, or 

 prothallium, as it is hence more generally called, usually produces several female 

 organs, which are commonly situated on the under side of the prothallus, in, or close 

 to, an indentation at the end farthest from the original spore and root-hairs. These 

 female organs, which are called " Archegonia," are shaped like jars with narrow necks 

 and no lips, and in the bottom of each there is a tiny cell, called an "ovule" or 

 ■" oosphere," which is the germ of the future plant. In the case of ferns the necks are 

 quite short, while in those of hepaticae they are long, like Florence oil-flasks. The 

 actual male organs, called " Antheridia," on the other hand, are situated close to, or 

 among, the root-hairs and are generally globular or pear-shaped in form. These last, 

 when ripe, burst and discharge minute organisms called " autherozoids " or " sperma- 

 tozoids," of various forms. Thus, those of Aspidia look like tiny eels, while those of 

 Adianta resemble two or three turns of the point of a screw, furnished with from eight to 

 twelve tails, and those of other ferns and cryptogams assume other shapes. In all cases, 

 however, they creep and wriggle about, till they find the mouth of a female organ, into 

 which they enter, and so reach the oosphere within it, on which they fasten and excite 

 it into growth. The whole process is far more analagous to what occurs in the case of 

 animals than to that which results in the reproduftion of vegetables, and this seems 

 to indicate that, in the early ages of the world, when cryptogams originated and 

 formed the bulk of terrestrial vegetation, the distinft lines of reproduction, which now 

 •charafterise animal and vegetable life, had not been differentiated. 



I see that, in the Chapter on cultivation of ferns, I omitted to note that plants, 



