12 



is called Clematis gentianoides. from its likeness to a 

 Gentian. 



The Ranunculus family, to which both Buttercup and 

 Clematis belong, is a rather large one, and is well dis- 

 tributed over the face of the earth, but it is poorly repre- 

 sented in Tasmania. We have a single species each of two 

 other genera, Caltha and Anemone, but they are rare 

 mountain plants, and not likely to be met with by 

 young collectors. As will be seen, the flowers in this family 

 are of a simple type ; the portions that go to make up each 

 set of flower elements are arranged spirally above one 

 another on the receptive portion of the stalk. It is 

 an advance in complexity when these are arranged in 

 definite circles. Again, each part is clearly independent 

 of its fellows; for instance, the petals are not united 

 in a tube, as in Heath, nor are the carpels joined to form 

 a complex pistil. For these reasons the type of flower in 

 the Ranunculus family is considered to be a primitive type; 

 that is, a form that was developed early in the evolution 

 of flowers, and from which more complex forms may have 

 been developed. This does not mean that the modified 

 flowers commonly met with were derived from Ranuncu- 

 lus-like flowers in lineal succession, but that they were 

 derived from ancestors showing somewhat similar simple 

 structure. Ranunculus flowers seem to have stood still. 

 Environment suited them, and they were quite able to live 

 and pass on descendants without the necessity for change. 



This tendency to persistence is common to all parts of 

 both animal and vegetable kingdoms. There is usually 

 room for a limited number of unprogressives, but that 

 limit is easily reached; then the struggle destroys the sur- 

 plus, except favoured individuals, who have some special 

 advantage which, diverging from the type, enables them 

 to maintain themselves. The result is that in both king 

 doms in the present day we find present not only advanced 

 types of beings, but intermixed with them all grades of 

 simpler forms, down to almost the most primitive. 

 Changed conditions exterminate many links. Organisms 

 that would thrive on our earth when it had a dense 

 atmosphere heavily charged with moisture and carbonic 

 acid, when the temperature was never very high, and never 

 at all low, would not exist anywhere with present con- 

 ditions. No link seems to be more thoroughly obliterated 

 than the early steps in the formation of living bodies. 



It must not be concluded from anything said above 

 that all apparently simple flowers are primitive. In the 



