324 BOTANICAL GAZETTE, [ December, 
CURRENT LITERATURE. 
Origin of floral structures. 
This is No. 63 of the “International Scientific Series.” There are 
many figures of flowers and their parts, and many observations on the 
characters, insect relations and variations of flowers, which have a value 
quite distinct from that of the theory which is advanced. 
Having laid aside the most fruitful principles which have been ap- 
plied to the elucidation of floral mechanisms, the author goes back to the 
“monde ambiant” of Geoffroy Saint Hilaire, and undertakes to account 
for the forms of flowers as the direct result of insect agency. Insects stim- 
ulate “the flowers till they become thoroughly adapted to their visitors.” 
Conversely, the neglect of insects is “ accompanied by corresponding deg- 
radations in the perianth, stamens and pollen.” The flower, “if it be vis- 
ited by many, will presumably take a form corresponding to the result- 
ant of the forces brought to bear upon it; if visited by few, it will shape 
itself in accordance with the requirements of its principal visitors.” 
This considers flowers as developing in a way subservient to the uses of 
insects, instead of as utilizing them as servants. Adaptations for cross- 
ing, being the result of the direct agency of insects, have nothing to do 
with any advantage resulting from cross-fertilization. The Darwinian 
theories of natural selection and of cross-fertilization are thus wholly repu- 
diated. But we are so far from being convinced that insects have given 
rise to useful variations that we even doubt whether they have induced 
any of the modifications which have been appropriated through natural 
selection. Moreover, it is easy to show that the characters of flowers are 
not what they would be expected to be according to the theory. In re- 
gard to irregularity he says: “The immediate causes, I repeat, I could 
recognize in the weight of the insect in front, the local irritation behind, 
due to the thrust of the insect’s head and probing for nectar, coupled 
with the absence of all strains upon the sides.” ; 
‘ But in sternotribe flowers the part which the insect touches the least 
is the strongest developed: Thus, in Papilionacez the banner is quite as 
as the two lower petals together, and often as large as the four 
they were developed. As an example of a flower in the first stage of ir 
regularity, the author cites Verbascum, a descendant of the ancient zygo- 
morphous type of Personales. The two genera with which it forms the 
* Henstow, Rev. GzorGe.—The Origin of Floral Structures through Insect and other 
cies. pp. xx, 350. New York: D. Appleton & Co. 1888 
