4 PRINCIPLES OP PLANT-TKEATOLOGY. 



the internodes in tlie liead itself would appear to be a 

 rare phenomenon. Weber has observed the flower-head 

 of the Dutch clover [Tri folium repens) transformed by 

 this means into a loose spike. Kirschleger saw the same 

 thing in the field-eryngo {Kryngiam campestre). The- 

 cause of the infrequency of solution of the capitulum; 

 into a loose spicate inflorescence may l^e that axillary 

 proliferation of these capitula is so frequent. 



Henslow describes and figures a very good example 

 of a spike of the mignonette {Bpseda odorata) becoming, 

 by proliferation of the flowers into racemes or panicles, 

 and elongation of the main axis of the spike, transformed 

 into a complex paniculate inflorescence. Much tha 

 same sort of thing he describes in the dark mullein 

 {Verhascum nigrum). 



In the rye-grass {Lolium perenne) the " spikelets," 

 representing congested inflorescences, may each pro- 

 liferate into a "spike" whose " spikelets" in their turn 

 may do the same ; in this way arise the varieties- 

 coviposituvi, rarnosissimum, asd panimdatum. 



Schmitz made some most interesting observations- 

 on abnormal inflorescences of the cypress-spurge- 

 {Euphorbia Gyparissias) which confirmed the conclu- 

 sions reached by Warming as a result of researches- 

 on the development. It is now recognized that the 

 "cyathium" of Euphorbia is an inflorescence, consisting^ 

 of a highly congested axis, bearing externally an appa- 

 rent whorl of small involucral bracts alternating with 

 large glands. Within are several scorpioid cymes of 

 male flowers surrounding a central female flower. 

 Schmitz observed instances in which the internodes 

 between the involucral bracts (normally suppressed, 

 and thus causing them to become verticillately ar- 

 ranged) had become developed, the bracts being spirally 

 arranged at wide vertical distances apart on the axis, 

 and each bearing in its axil a stamen (PI. XXIX, fig. 1). 

 This last fact proves that the supposed staanen of 

 Euphorbia is in reality an entire flower. As there is no 

 .urticulation present in these axillary " stamens," the 



