The subject is in many ways important for us, more especially as the sterility of species when first crossed, and that of their hybrid offspring, cannot have been acquired, as I shall show, by the preservation of successive profitable degrees of sterility.
Gai hau inportantea da guretzat alderdi askotatik, bereziki espezieen antzutasuna lehen aldiz gurutzatzen direnean eta haien ondorengo hibridoena ezin erdiets zezakeelako, gero frogatuko duduan moduan, hurrenez hurreneko antzutasun maila onuragarrien bidez.