264 Professor Henslow's Examination 



kind of granules, and I could see their explosion accompanied 

 by successive and sudden contractions and dilatations of the 

 grains themselves. But I could never detect any cloud of smaller 

 granules similar to that which was exploded from the pollen of 

 the parents, and which always proceeds from the grain by a 

 continuous and slow emission, whereas the larger granules in 

 the hybrid were discharged at intervals, and by separate efforts, 

 and lay scattered at a distance from each other over the field of 

 view (Fig./) 



Koelreuter has given it as his decided opinion, derived from 

 his numerous experiments, that true hybrids never reproduce their 

 kind. Later experimenters have doubted this fact, and some seem 

 to consider the question as quite settled to the contrary, at least 

 with respect to the possibility of fertilizing a hybrid by the pollen 

 of one or other of the parent species. But in prosecuting this en- 

 quiry we must be very cautious to keep in view the perfect 

 distinctness of the two questions, whether it be probable and 

 whether it be possible that hybrids should reproduce their kind. 

 If it be possible that a true hybrid may do so, it may still be 

 very improbable, from some deficiency in that connection of cir- 

 cumstances, of whatever description it be, which is essential 

 to secure the fertilization of the ovule. We might imagine* for 

 instance, so great a discrepancy to exist between the respective 

 circumstances suited to the healthy action of its vegetative and 

 reproductive functions, that although one climate may be adopted 

 for securing the former, another might be required for obtaining 



* This hypothesis is thrown out merely in the way of illustration, and not as likely to, 

 afford any solution of the cause of infertility observable in Hybrids, at least in most of 

 them. 



