NOTES AND CONCLUSIONS. 



375 



doubtless because chiefly of the small cumber and the 

 kinds of hybrids studied. In summing up the characters 

 thai are the same as or inclined to the seed parenl and the 

 pollen parent, respectively, it was found in the 1,018 

 starch reactions thai the seed parenl is, on the whole, 

 distinctly more potent than the pollen parent, while in 

 959 tissue characters the parental influences are equal. 



Si'ini s Pakents vi.i;m s St.x I'aki.ntx. 



The parental properties referred to in the precedin 

 section are, in an important sense, illusory, because the] 

 indicate sexual instead of species characters. The terms 

 seed parenl, and pollen parent have lien used in this re- 

 search in the conventional sense of the botanist and horti- 

 culturist, that is. without necessarily implying or even 

 inferring unisexuality of the plants. This u.sige, to- 

 gether with the employment of the signs 9 and i , ma\ 

 carry the impression that the parents of the hybrids 

 are correspondingly female and male, but all of the 

 parent- are flowering plants in which in each individual 

 there are produced both female and male gametes. Each 

 plant is, therefore, female or male in reproduction in 

 accordance with whether it furnishes the seed or the 

 pollen, irrespective of the actual sex of the organism. 

 A concrete illustration of this paradoxical statement is 

 found, for instance, in Cypripedium spencerianum and 

 ('. vfflosum, which have been reciprocally crossed, yield- 

 ing the hybrids ''. lathamianum and <'. lathiamianum 

 inversum, these hybrids not being identical hut verj 

 closely resembling each other (page 338 ei seq.). In the 

 first cross the seed of C. spencerianum was fertilized h\ 

 the pollen of ('. villosum, and in the second cross the 

 pollen of ('. spencerianum fertilized the seed of ('. vil- 

 losum, thus reversing the parentage. Inasmuch as each 

 plant is precisely the same in both crosses, it is evident 

 that the properties ascribed to ('. spencerianum as the 

 seed parent and the pollen parent. respectively, are identi- 

 cal and therefore that they are. as far as we can discern. 

 peculiarities of species and not of sex. However, the 

 differences in the offspring of reciprocal crosses show that 



while the .- 1 and the pollen carry species-characters 



they also transmit certain obscure properties that are 

 peculiar to cadi of the sex elements. 



All living tissues have without question species-types 

 of metabolism, and. as a. corollary, Bpi 

 plex organic metab ding memoir, Car- 



negie [nstitution of Washington, Pub. No. 1 :;'>. page 12) ; 

 and if the tissues are further characterized by femal 

 or maleness, they muel have the corresponding sex-types. 

 In bisexual or monoecious organisms, such as the plants 

 n -I in this research for the sources of the -larches and 

 tissues, tic structures, processes, and product-, with the 

 exception of those belonging to the primary sex or 

 are without determinable sex characters, yet for well- 

 known reasons it is certain that they possi erentl] 

 potentialities o es. fn unisexual organisms, t 

 certain plants and in all normal mammalia, there must 

 be both species-types and sex-types. Therefore, b. 

 first group of the properties are broadly speaking or pre- 

 eminently those of species, and in the second the 



ies and sex. 



That there are 3pecies-types is convincingly shown 

 by the distinguishing featun ' that there 



are very definite sex-types has been rendered posit ive, 



especially by recent investi I ^r instance, in 



gynandromorphs (a noted in a bullfinch by Poll, in a 

 chaffinch by Weber, in a pheasant b Bond, and in men, 

 ■ii 1 1 ea pigs, oralis, bees, ants, butterflies, and moths 

 h\ various « riters | thi I rm tun or of 



the anterior and po tei ior parts <■! the body, or of differ- 

 ent organs or of parts of an organ are oppo 

 Bexed. Geoffrey Smith found th of female 



and male spider crabs differ, and Stecke in investigai ions 



with moths noted that not only do the bloi 

 differ but also are as much unlike as are those of indi- 

 viduals of the same sex of different i 

 of woman and man, and of the sexes <>f i other 

 mammals, are not identical. The ovaries and 



are specifically female and male organs, and the egg, 



spermatozoon, and sex horm a an- similarly - 



Moreover, during t' - ence "- the ^ermplasm, and 



even in .-on rganisms long aft, ■ imeni has 



proceeded, there is a period of sexual plasticity during 

 which various factor- may be directly operative on the 

 egg or indirectly through the parent, or directly on the 

 metabolic processes of the individual, to i the 



development of either sex or of either female or male 

 secondary characters, as the case may he. and hen 

 corresponding female or male types of m i ami 



metabolites. In studies of the pupa of butterflies, Stand- 

 fuss found that by the influem mperature 

 female can be made to assume the male type. Geoffrey 

 Smith noted that the sacctilinated male spider crab (that 

 is partially or completely parasitically castrated) he- 

 comes markedly feminized, even to the extent of rudi- 

 mentary eggs being formed in the test* - Riddle records 

 in studies of pigeon eggs a transmutability so marked 

 that v^iS< having one sex ten v be caused • 

 come oppositely sexed. Steinach and others in ovarian 

 ami testicular transplantation experii shown 

 that the female can he masculinized and the male femi- 

 nized. .Moreover, the potent influences of food, of an 

 < xcess or deficit of water in the t^^, of the energy of 

 oxidative metabolism, and of light on se I are 

 well known. And in the human being indications of 

 female and male types of metabolism and metabolites 

 ■ire to lie found among differences in the sexes in bodily 

 structures, in the composition of the blood and certain 

 other parts, in the actions of a number of medicinal sul>- 



and certain internal secretions, in the pi 

 of the sex hormones and of ler substances that 



are produced by sex organs other than the ovaries and 

 testes, in basal metabolism, in psyi hie phenomena, eh . 



The factor or factors that determine - are 



not known, nor have we much definite knowledge of those 

 which control sex-type-, but il may justly be assumed that 

 what is learned of one is applicable in principle to the 

 other. Since the discover] of the sex hormones there has 

 been a tendency generally to attribute to them the deter- 

 mination of secondary sex characters, but there are 

 reasons for believing that other substances, as yet un- 

 known, may lie similarly potent. Thus, Meisenheimer 

 showed by the results of experiments with the Ian 

 the gypsy moth that try sex characters are devel- 



oped without material mod the removal of 



the ovaries and testes : aid it is e\ ident that in gynan 

 morphs both sex hormones circulate throughout the 

 organism, and thus reach every tissue, yet some parts 



