Teratolosrical Notes. 91 



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The occurrence of these limestones at the anticlinal 

 folds of the formation has been noticed in a general way 

 by Dr. Ells, of the Geological Survey staff, who is now en- 

 gaged in mapping the general geology of a very large 

 district north of the Ottawa River, extending from Ottawa 

 .city eastward, nearly to Montreal. The writer, however, 

 believes that this is the first attempt to explain in detail 

 the reason of this association on the basis of subsequent 

 alteration in place, and to put forward a theory which 

 should harmonize all the features observable both in the 

 larger and more definite areas and in the smaller and scat- 

 tering patches found throughout the district. 



Since writing the above I understand from Dr. Selwyn, the Director of the 

 Geological Survey, that in some correspondence he had with Messrs. Rowney 

 and King in regard to their book on Rock Metamorphism, issued in connection 

 with the Eozoon controversy in 1881, he wrote as follows : " I am led to believe 

 that the two kinds of limestone or dolomite have had a distinct origin and that 

 the non-fossiliferous and generally crystalline set are newer than the strata 

 with which they are associated. Nearly if not quite all our Laurentian and 

 Huronian limestones seem to me to have this non-contemporaneous character 

 notwithstanding that they conform more or less perfectly with the lamination 

 and with the larger flexures of the associated gneiss." 



Teratological Notes. 



By D. P. Penh allow, McGill University. 



Marked departures from the ordinary course of develop- 

 ment in plants are interesting, and often instructive, as 

 throwing additional light upon the morphological charac- 

 ter of organs, the original features of which have become 

 lost in the course of development and adaptation to special 

 functions. This is particularly true where these changes 

 are of the nature of reversions to the primitive type of 

 structure The present notes are designed to draw atten- 

 tion to a few instances of such reversions which have lately 

 come under notice, and which have already served an im- 

 portant purpose in the instruction of students. During the 

 past winter, Mr. N. N. Evans brought to my notice a com- 

 mon cultivated tulip which displayed an alteration in some 

 respects most unusual. The flower was perfectly normal 



