Filoza, was a silver grey, who very possibly could have had the genetic formula, 'ayay chch' or 'ayat'. Filoza's father, the black stud, Tom du Progres, most certainly carried the grey 'ch' gene. When Tom was bred to his half sister, the black bitch, Miss Elda, he produced the grey Filoza. And, when Tom was in turn bred to his grey daughter (Filoza), on May 25, 1933 he produced 3 blacks (#57783-57785) and 3 silver greys registered in the "Autre que noir ou fauve' category (#57786-57788). Genetically, in order to produce these results, Tom had to carry both the 'ch' gene, and either the fawn 'ay' gene or the recessive black 'at' gene. BBA pix|
The creation of the long hair other than fawn or black variety was abundantly justified since the breed was able to keep some excellent, typical subjects which, when bred to either Groenendael or Tervuren could produce some equally valuable offspring. These offspring would then be classified as either Groenendale or Tervuren (or 'Autre), according to their color.
The most typical case in Belgium was that of the silver grey Filoza, who as the grandmother of Tan de l'Infernal holds a place of distinction among today's blacks. BBA p50
1942 - The first Belgian war-time gathering of Berger Belge to evaluate the existing stock. Ilion, a black with a grey undercoat, out of the grey Filoza, is highly recommended for breeding.
1945 - Birth of the famous black, Tan de l'Infernal, sired by Ilion. BBA p8
sire Groenendael Tom du Progres LOSH 18340
dam Groenendael Miss Elda LOSH 51347