NOTES AND CONCLUSIONS. 





doubtless because chiefly of the email number and Un- 

 kind* of hybrids studied. In i-uniming up the elm 

 that are thesanie a.-, or in.'iin.-.l to the sovd parent and the 

 pollen parent, respectively, it was found id 



xxl parvi the wliole, 



di.-tmctly m.>n> potent than the pollen parent, while in 

 959 tissue character- the parental influences are equal. 



Srt tam I'M:I nil M:M UUC.NTS. 



The parental pro|H-rtics referred to in the preo 



n arc. in an important M-n-r. illusory, because they 

 indicate se\ual instead of species characti in-m- 



seed parent and pollen parent have !-.-n u-.-l in this rc- 

 i in the comciitiiiiial sense of th. and horti- 



eulturi.st. that is. without necessarily implying or 

 inferring uni-cMiality of the plant 

 gethcr with the employment of tbt { 9 and i , may 

 n tlnit the jwrcnts of tin- hybrid's 

 arc . y female and male, bat all of the 



:s are tlowenny plants in which in each individual 

 tlierv are prodiuvd U>th female and male gamete*, 

 plant is, therefore, female or male in reproduction in 

 e with whether it furnishes the seed or the 

 ;x>llen, ir <>f the actual sex of the orgn 



A concrete illustration of this |>aradoxu-al statement in 

 found, for instance, in ('iijiriptdium sitencrrianum and 

 'lofum. which have Uvn ndpVMuh crossed, yield- 

 "ie hybrids ('. lathamianum and ('. lathiamianum 

 unt. these hybrids not being identical but very 

 ly resembling each other (page :W8 r( *<</.). In the 

 first eross the need of ( \,nnim was fertilized by 



the |M.Heii of r. \-\ll<:*um, and in the s<-cond cross the 

 |H)||en of f. $pcnceritiniim fertilised the seed of < 

 losum, thu* re\er-in<; the parentage. Inasmuch as each 

 plain --ly the simc in both en-;-.- . idi-nt 



that the properties nscriled to C. sprnctnanum as the 

 seed parent and the |x>Ileii |>arent, respectively, are identi- 

 cal and therefore that they arc, as far as we can discern, 

 f s|x-cies and not of sex. However, the 

 dinVrcmvs in the offspring of n-cipnx-al crosses show that 

 while the vd and the |x.llen carry species-characters 

 they nlo transmit ii-rtain obscure properties that arc 

 j>cculiar to each of the sex elem. 



living tissues have without question fp*rif*-type* 

 of nietalxilism, and, as a corolla r 



organic nietalx.lites (see pn-o-dinu' memoir. C'ar- 

 negie Institution of Wn-ihin^ton, 1'ub 

 and if the tissues are further charaotiri/.e.l by femaleneso 

 or malenww. they mu.*t have the corresponding *ei-type*. 

 In bisexual or >ua organisms, such as the plants 



search for the sources of the starches and 

 tissu' processes, and products, with the 



of th'*> In-longing to the primary sex organs, 

 arc without determinal . yet for well- 



known reasons it is certain that they possem inherently 

 potentialities of both sexes. In unisexual < . as in 



certain plant* and in all normal mammalia, there mint 

 be both *|>c< ies-types and HX-I n-. in the 



first group of the properties are broadly speaking or pre- 

 eminently those of species, and in the second those of 

 species and sex. 



That there are species-types i* convincingly shown 

 by the distinjniishing features of species; and that there 

 are very definite sex-types has been rendered positive, 



especially by recent investigations. For '"tttmrt! in 



Iromorpha (u noted in a bulltim-! in a 



chaffinch by Weber, in a pheasant by Bood, and in OMB, 

 dogs, guinea-pigs, crabs, bee*, anU, but i- r :! . .. and moths 



th<> structure* of the two aidei 

 1 interior parts of the body, or of <i 

 <rgans or of parts of an organ are 

 mixed. Geoffrey Smith found that tho bloods of female 

 and male spider .-nil* dilTer, and Stcrke in iuvtwtigationa 

 w ith moths noted that not only do th< f the sexes 



i tier but also are as much unlike as are those of 

 viduaU of the same- sex of different specioa. The bloods 

 of woman and man. and of the -e\. .,f certain other 

 mammals, are not identical. The orariea and testicles 

 are specifically female and male organs, and the "ggi 

 spermatozoon, and sex hormones are similarly send. 

 Moreover, during the existence of the gcrmplasm, and 

 even in some organism* long after meat has 



proceeded, there is a period of sexual pla 

 which various factors may be directly operative on the 

 egg or indirectly through the parent, or directly on the 

 >lic processes of the individual, to lead to the 

 development of either sex or of either female or male 

 secondary characters, as the case may be, and hence to 

 corresponding female or male types of metabolism and 

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

 fuss found that by the influence of temperature the 

 female can be made to assume the male type, Qeoffn-v 

 Smith noted that the sacculinatcd male spider crab (that 

 is partially or completely paraaitically castratnl i 

 comes markedly feminized, even to the extent of rudi- 

 mentary eggs being formed in the testes. Kiddle ni-ord 

 in studies of pigeon eggs a tranomu lability so marked 

 that eggs having one sex tendency may be caused to be- 

 come oppositely sexed. Steinach and others in ovarian 

 and testieular transplantation experiment* hare shown 

 that the female can be masculinized and the male femi- 

 nized. Moreover, the potent influent-en of food, of an 

 excess or deficit of water in the cjrg. of the energy of 

 oxidative metabolism, and of light on * 1 are 



well known. And in the human being indication* of 

 female and male types of mctaholium and metabolites 

 are to be found among difference* in the sexes in l.!ilv 

 structure*, in the composition of the blood and certain 

 other parts, in the actions of a number of medicinal sub- 

 stances and certain internal secretions, in the prop- 

 of the sex hormones and of some other substances that 

 are produced by sex organs other than the ovaries and 

 testes, in basal metabolism, in psychic phenomena, etc. 



The factor or factors that determine species-types are 

 not known, nor have we much definite knowledge of those 

 which control sex -types, but it may justly be assumed thai 

 what is learned of one is applicable in principle to the 

 ndior. Since the discovery of the sex hormones them bus 

 been a tendency generally to attribute to them the deter- 

 mination of secondary sex characters, but there an 

 reasons for believing that other substances, as yet un- 

 known, may be similarly potent. Thus, Meisenheimer 

 showed by the result* of experiments with the larva* of 

 the gypsy moth thai secondary sex characters are devel- 

 oped without material modification after the removal of 

 the ovaries and testea ; and it is evident that in gynar 

 morphs both sex hormones circulate throughout the 

 organism, and thus reach every tissue, yet some parts 



